diff --git a/cardano-testnet/cardano-testnet.cabal b/cardano-testnet/cardano-testnet.cabal
index 0343db57ec8..bd84a3d9954 100644
--- a/cardano-testnet/cardano-testnet.cabal
+++ b/cardano-testnet/cardano-testnet.cabal
@@ -173,6 +173,7 @@ test-suite cardano-testnet-test
                         Cardano.Testnet.Test.Cli.Babbage.Transaction
                         Cardano.Testnet.Test.Cli.Conway.DRepRetirement
                         Cardano.Testnet.Test.Cli.Conway.Plutus
+                        Cardano.Testnet.Test.Cli.Conway.RepeatedCertificatesInTransaction
                         Cardano.Testnet.Test.Cli.Conway.StakeSnapshot
                         Cardano.Testnet.Test.Cli.KesPeriodInfo
                         Cardano.Testnet.Test.Cli.Queries
diff --git a/cardano-testnet/src/Testnet/Components/SPO.hs b/cardano-testnet/src/Testnet/Components/SPO.hs
index ba73c57c7dc..1f1dc8ecaf6 100644
--- a/cardano-testnet/src/Testnet/Components/SPO.hs
+++ b/cardano-testnet/src/Testnet/Components/SPO.hs
@@ -1,14 +1,16 @@
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE NumericUnderscores #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
 
 
 module Testnet.Components.SPO
   ( checkStakeKeyRegistered
-  , convertToEraFlag
   , createScriptStakeRegistrationCertificate
   , createStakeDelegationCertificate
   , createStakeKeyRegistrationCertificate
+  , createStakeKeyDeregistrationCertificate
   , decodeEraUTxO
   , registerSingleSpo
   ) where
@@ -115,12 +117,12 @@ createStakeDelegationCertificate
   -> String -- ^ Pool id
   -> FilePath
   -> m ()
-createStakeDelegationCertificate tempAbsP anyCera delegatorStakeVerKey poolId outputFp =
+createStakeDelegationCertificate tempAbsP (AnyCardanoEra cEra) delegatorStakeVerKey poolId outputFp =
   GHC.withFrozenCallStack $ do
     let tempAbsPath' = unTmpAbsPath tempAbsP
-    void $ execCli
-      [ "stake-address", "delegation-certificate"
-      , convertToEraFlag anyCera
+    execCli_
+      [ eraToString cEra
+      , "stake-address", "stake-delegation-certificate"
       , "--stake-verification-key-file", delegatorStakeVerKey
       , "--stake-pool-id", poolId
       , "--out-file", tempAbsPath' </> outputFp
@@ -131,44 +133,71 @@ createStakeKeyRegistrationCertificate
   => TmpAbsolutePath
   -> AnyCardanoEra
   -> FilePath -- ^ Stake verification key file
+  -> Int -- ^ deposit amount used only in Conway
   -> FilePath -- ^ Output file path
   -> m ()
-createStakeKeyRegistrationCertificate tempAbsP anyCEra stakeVerKey outputFp =
-  GHC.withFrozenCallStack $ do
-    let tempAbsPath' = unTmpAbsPath tempAbsP
-
-    void $ execCli
-      [ "stake-address", "registration-certificate"
-      , convertToEraFlag anyCEra
-      , "--stake-verification-key-file", stakeVerKey
-      , "--out-file", tempAbsPath' </> outputFp
-      ]
+createStakeKeyRegistrationCertificate tempAbsP (AnyCardanoEra cEra) stakeVerKey deposit outputFp = GHC.withFrozenCallStack $ do
+  sbe <- requireEon cEra
+  let tempAbsPath' = unTmpAbsPath tempAbsP
+      extraArgs = caseShelleyToBabbageOrConwayEraOnwards
+                    (const [])
+                    (const ["--key-reg-deposit-amt", show deposit])
+                    sbe
+  execCli_ $
+    [ eraToString cEra
+    , "stake-address", "registration-certificate"
+    , "--stake-verification-key-file", stakeVerKey
+    , "--out-file", tempAbsPath' </> outputFp
+    ]
+    <> extraArgs
 
 createScriptStakeRegistrationCertificate
   :: (MonadTest m, MonadCatch m, MonadIO m, HasCallStack)
   => TmpAbsolutePath
   -> AnyCardanoEra
   -> FilePath -- ^ Script file
-  -> Int -- ^ Registration deposit amount
+  -> Int -- ^ Registration deposit amount used only in Conway
   -> FilePath -- ^ Output file path
   -> m ()
-createScriptStakeRegistrationCertificate tempAbsP anyCEra scriptFile deposit outputFp =
+createScriptStakeRegistrationCertificate tempAbsP (AnyCardanoEra cEra) scriptFile deposit outputFp =
   GHC.withFrozenCallStack $ do
+    sbe <- requireEon cEra
     let tempAbsPath' = unTmpAbsPath tempAbsP
-
-    void $ execCli
-      [ anyEraToString anyCEra
+        extraArgs = caseShelleyToBabbageOrConwayEraOnwards
+                      (const [])
+                      (const ["--key-reg-deposit-amt", show deposit])
+                      sbe
+    execCli_ $
+      [ eraToString cEra
       , "stake-address", "registration-certificate"
       , "--stake-script-file", scriptFile
-      , "--key-reg-deposit-amt", show deposit
       , "--out-file", tempAbsPath' </> outputFp
       ]
+      <> extraArgs
 
-
--- TODO: Remove me and replace with new era based commands
--- i.e "conway", "babbage" etc
-convertToEraFlag :: AnyCardanoEra -> String
-convertToEraFlag era = "--" <> anyEraToString era  <> "-era"
+createStakeKeyDeregistrationCertificate
+  :: (MonadTest m, MonadCatch m, MonadIO m, HasCallStack)
+  => TmpAbsolutePath
+  -> AnyCardanoEra
+  -> FilePath -- ^ Stake verification key file
+  -> Int -- ^ deposit amount used only in Conway
+  -> FilePath -- ^ Output file path
+  -> m ()
+createStakeKeyDeregistrationCertificate tempAbsP (AnyCardanoEra cEra) stakeVerKey deposit outputFp =
+  GHC.withFrozenCallStack $ do
+    sbe <- requireEon cEra
+    let tempAbsPath' = unTmpAbsPath tempAbsP
+        extraArgs = caseShelleyToBabbageOrConwayEraOnwards
+                      (const [])
+                      (const ["--key-reg-deposit-amt", show deposit])
+                      sbe
+    execCli_ $
+      [ eraToString cEra
+      , "stake-address" , "deregistration-certificate"
+      , "--stake-verification-key-file", stakeVerKey
+      , "--out-file", tempAbsPath' </> outputFp
+      ]
+      <> extraArgs
 
 -- | Related documentation: https://github.com/input-output-hk/cardano-node-wiki/blob/main/docs/stake-pool-operations/8_register_stakepool.md
 registerSingleSpo
@@ -192,7 +221,6 @@ registerSingleSpo
 registerSingleSpo identifier tap@(TmpAbsolutePath tempAbsPath') cTestnetOptions execConfig
                   (fundingInput, fundingSigninKey, changeAddr) = GHC.withFrozenCallStack $ do
   let testnetMag = cardanoTestnetMagic cTestnetOptions
-      eraFlag= convertToEraFlag $ cardanoNodeEra cTestnetOptions
 
   workDir <- H.note tempAbsPath'
 
@@ -251,11 +279,12 @@ registerSingleSpo identifier tap@(TmpAbsolutePath tempAbsPath') cTestnetOptions
 
   -- 5. Create registration certificate
   let poolRegCertFp = spoReqDir </> "registration.cert"
+  let era = cardanoNodeEra cTestnetOptions
 
   -- The pledge, pool cost and pool margin can all be 0
   execCli_
-    [ "stake-pool", "registration-certificate"
-    , "--babbage-era"
+    [ anyEraToString era
+    , "stake-pool", "registration-certificate"
     , "--testnet-magic", show @Int testnetMag
     , "--pool-pledge", "0"
     , "--pool-cost", "0"
@@ -272,15 +301,14 @@ registerSingleSpo identifier tap@(TmpAbsolutePath tempAbsPath') cTestnetOptions
 
   -- Create pledger registration certificate
 
-  createStakeKeyRegistrationCertificate
-    tap
-    (cardanoNodeEra cTestnetOptions)
+  createStakeKeyRegistrationCertificate tap era
     poolOwnerstakeVkeyFp
+    2_000_000
     (workDir </> "pledger.regcert")
 
   void $ execCli' execConfig
-    [ "transaction", "build"
-    , eraFlag
+    [ anyEraToString era
+    , "transaction", "build"
     , "--change-address", changeAddr
     , "--tx-in", Text.unpack $ renderTxIn fundingInput
     , "--tx-out", poolowneraddresswstakecred <> "+" <> show @Int 5_000_000
@@ -310,7 +338,7 @@ registerSingleSpo identifier tap@(TmpAbsolutePath tempAbsPath') cTestnetOptions
            ]
   -- TODO: Currently we can't propagate the error message thrown by checkStakeKeyRegistered when using byDurationM
   -- Instead we wait 15 seconds
-  threadDelay 15_000000
+  threadDelay 15_000_000
   -- Check the pledger/owner stake key was registered
   delegsAndRewards <-
     checkStakeKeyRegistered
@@ -331,4 +359,3 @@ registerSingleSpo identifier tap@(TmpAbsolutePath tempAbsPath') cTestnetOptions
               poolColdVkeyFp
               currentRegistedPoolsJson
   return (poolId, poolColdSkeyFp, poolColdVkeyFp, vrfSkeyFp, vrfVkeyFp)
-
diff --git a/cardano-testnet/src/Testnet/Property/Utils.hs b/cardano-testnet/src/Testnet/Property/Utils.hs
index 804c65bb3fe..30c5a673868 100644
--- a/cardano-testnet/src/Testnet/Property/Utils.hs
+++ b/cardano-testnet/src/Testnet/Property/Utils.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE NumericUnderscores #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
 
 module Testnet.Property.Utils
   ( integration
@@ -19,6 +20,7 @@ module Testnet.Property.Utils
   , getShelleyGenesisHash
 
   , decodeEraUTxO
+  , requireEon
   ) where
 
 import           Cardano.Api
@@ -36,6 +38,7 @@ import           Data.Aeson.Key
 import           Data.Aeson.KeyMap hiding (map)
 import qualified Data.ByteString as BS
 import           Data.Text (Text)
+import           Data.Typeable
 import           Data.Word
 import           GHC.Stack
 import qualified GHC.Stack as GHC
@@ -44,6 +47,8 @@ import qualified System.Environment as IO
 import           System.Info (os)
 import qualified System.IO.Unsafe as IO
 
+import           Testnet.Start.Types
+
 import qualified Hedgehog as H
 import qualified Hedgehog.Extras as H
 import           Hedgehog.Internal.Property (MonadTest)
@@ -122,3 +127,18 @@ runInBackground act = void . H.evalM $ allocate (H.async act) cleanUp
 
 decodeEraUTxO :: (IsShelleyBasedEra era, MonadTest m) => ShelleyBasedEra era -> Aeson.Value -> m (UTxO era)
 decodeEraUTxO _ = H.jsonErrorFail . Aeson.fromJSON
+
+
+requireEon :: forall eon era m. Eon eon
+           => HasCallStack
+           => Typeable (eon era)
+           => MonadTest m
+           => CardanoEra era -- ^ node era
+           -> m (eon era)
+requireEon era = withFrozenCallStack $
+  maybe
+    (H.note_ errorMessage >> H.failure)
+    pure
+    (forEraMaybeEon era)
+  where
+    errorMessage = "Cannot witness '" <> show (typeRep (Proxy @(eon era)))  <> "' in " <> eraToString era <> " era."
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/LeadershipSchedule.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/LeadershipSchedule.hs
index 80afa1b97c1..bce8115ecaf 100644
--- a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/LeadershipSchedule.hs
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/LeadershipSchedule.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE BlockArguments #-}
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE DisambiguateRecordFields #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE NumericUnderscores #-}
@@ -135,6 +134,7 @@ hprop_leadershipSchedule = H.integrationRetryWorkspace 2 "babbage-leadership-sch
     tempAbsPath
     (cardanoNodeEra cTestnetOptions)
     testDelegatorVkeyFp
+    2_000_000
     testDelegatorRegCertFp
 
   -- Test stake address deleg  cert
@@ -161,12 +161,12 @@ hprop_leadershipSchedule = H.integrationRetryWorkspace 2 "babbage-leadership-sch
   UTxO utxo2 <- H.noteShowM $ decodeEraUTxO sbe utxo2Json
   txin2 <- H.noteShow =<< H.headM (Map.keys utxo2)
 
-  let eraFlag = convertToEraFlag $ cardanoNodeEra cTestnetOptions
+  let eraString = anyEraToString $ cardanoNodeEra cTestnetOptions
       delegRegTestDelegatorTxBodyFp = work </> "deleg-register-test-delegator.txbody"
 
   void $ execCli' execConfig
-    [ "transaction", "build"
-    , eraFlag
+    [ eraString
+    , "transaction", "build"
     , "--change-address", testDelegatorPaymentAddr -- NB: A large balance ends up at our test delegator's address
     , "--tx-in", Text.unpack $ renderTxIn txin2
     , "--tx-out", utxoAddr <> "+" <> show @Int 5_000_000
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/Transaction.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/Transaction.hs
index 616dc3193e9..ff14b15057d 100644
--- a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/Transaction.hs
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Babbage/Transaction.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE DisambiguateRecordFields #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/DRepRetirement.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/DRepRetirement.hs
index 1ece0bbec81..279359f1e4e 100644
--- a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/DRepRetirement.hs
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/DRepRetirement.hs
@@ -7,12 +7,6 @@
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
 
-#if __GLASGOW_HASKELL__ >= 908
-{-# OPTIONS_GHC -Wno-x-partial #-}
-#endif
-
-{- HLINT ignore "Use head" -}
-
 module Cardano.Testnet.Test.Cli.Conway.DRepRetirement
   ( hprop_drep_retirement
   ) where
@@ -64,7 +58,7 @@ hprop_drep_retirement = H.integrationRetryWorkspace 2 "drep-retirement" $ \tempA
   TestnetRuntime
     { testnetMagic
     , poolNodes
-    , wallets
+    , wallets=wallet0:_
     , configurationFile
     }
     <- cardanoTestnetDefault fastTestnetOptions conf
@@ -111,7 +105,7 @@ hprop_drep_retirement = H.integrationRetryWorkspace 2 "drep-retirement" $ \tempA
        , "--out-file", drepCertFile n
        ]
 
-  txin1 <- findLargestUtxoForPaymentKey epochStateView sbe $ wallets !! 0
+  txin1 <- findLargestUtxoForPaymentKey epochStateView sbe wallet0
 
   -- Submit registration certificates
   drepRegTxbodyFp <- H.note $ work </> "drep.registration.txbody"
@@ -120,7 +114,7 @@ hprop_drep_retirement = H.integrationRetryWorkspace 2 "drep-retirement" $ \tempA
   H.noteM_ $ H.execCli' execConfig
     [ "conway", "transaction", "build"
     , "--tx-in", Text.unpack $ renderTxIn txin1
-    , "--change-address", Text.unpack $ paymentKeyInfoAddr $ wallets !! 0
+    , "--change-address", Text.unpack $ paymentKeyInfoAddr wallet0
     , "--certificate-file", drepCertFile 1
     , "--certificate-file", drepCertFile 2
     , "--certificate-file", drepCertFile 3
@@ -131,7 +125,7 @@ hprop_drep_retirement = H.integrationRetryWorkspace 2 "drep-retirement" $ \tempA
   H.noteM_ $ H.execCli' execConfig
     [ "conway", "transaction", "sign"
     , "--tx-body-file", drepRegTxbodyFp
-    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair $ wallets !! 0
+    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair wallet0
     , "--signing-key-file", drepSKeyFp 1
     , "--signing-key-file", drepSKeyFp 2
     , "--signing-key-file", drepSKeyFp 3
@@ -161,12 +155,12 @@ hprop_drep_retirement = H.integrationRetryWorkspace 2 "drep-retirement" $ \tempA
 
   H.noteM_ $ H.execCli' execConfig
     [ "conway", "query", "utxo"
-    , "--address", Text.unpack $ paymentKeyInfoAddr $ wallets !! 0
+    , "--address", Text.unpack $ paymentKeyInfoAddr wallet0
     , "--cardano-mode"
     , "--out-file", work </> "utxo-11.json"
     ]
 
-  txin2 <- findLargestUtxoForPaymentKey epochStateView sbe $ wallets !! 0
+  txin2 <- findLargestUtxoForPaymentKey epochStateView sbe wallet0
 
   drepRetirementRegTxbodyFp <- H.note $ work </> "drep.retirement.txbody"
   drepRetirementRegTxSignedFp <- H.note $ work </> "drep.retirement.tx"
@@ -174,7 +168,7 @@ hprop_drep_retirement = H.integrationRetryWorkspace 2 "drep-retirement" $ \tempA
   H.noteM_ $ H.execCli' execConfig
     [ "conway", "transaction", "build"
     , "--tx-in", Text.unpack $ renderTxIn txin2
-    , "--change-address", Text.unpack $ paymentKeyInfoAddr $ wallets !! 0
+    , "--change-address", Text.unpack $ paymentKeyInfoAddr wallet0
     , "--certificate-file", dreprRetirementCertFile
     , "--witness-override", "2"
     , "--out-file", drepRetirementRegTxbodyFp
@@ -183,7 +177,7 @@ hprop_drep_retirement = H.integrationRetryWorkspace 2 "drep-retirement" $ \tempA
   H.noteM_ $ H.execCli' execConfig
     [ "conway", "transaction", "sign"
     , "--tx-body-file", drepRetirementRegTxbodyFp
-    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair $ wallets !! 0
+    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair wallet0
     , "--signing-key-file", drepSKeyFp 1
     , "--out-file", drepRetirementRegTxSignedFp
     ]
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/Plutus.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/Plutus.hs
index 8be8df0831b..6c1a09f6311 100644
--- a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/Plutus.hs
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/Plutus.hs
@@ -10,7 +10,6 @@
 {- HLINT ignore "Redundant id" -}
 {- HLINT ignore "Redundant return" -}
 {- HLINT ignore "Use head" -}
-{- HLINT ignore "Use let" -}
 
 module Cardano.Testnet.Test.Cli.Conway.Plutus
   ( hprop_plutus_v3
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/RepeatedCertificatesInTransaction.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/RepeatedCertificatesInTransaction.hs
new file mode 100644
index 00000000000..2ba09e53563
--- /dev/null
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/RepeatedCertificatesInTransaction.hs
@@ -0,0 +1,134 @@
+{-# LANGUAGE DisambiguateRecordFields #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE NumericUnderscores #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
+
+module Cardano.Testnet.Test.Cli.Conway.RepeatedCertificatesInTransaction where
+
+import           Cardano.Api hiding (Value)
+
+import           Cardano.Testnet
+
+import           Prelude
+
+import           Control.Monad (void)
+import qualified Data.Aeson as A
+import qualified Data.Aeson.Lens as L
+import           Data.String
+import qualified Data.Text as Text
+import           Lens.Micro
+import           System.FilePath ((</>))
+import qualified System.Info as SYS
+
+import           Testnet.Components.Configuration (anyEraToString)
+import           Testnet.Components.Query
+import           Testnet.Components.SPO
+import           Testnet.Process.Cli hiding (File)
+import qualified Testnet.Process.Run as H
+import           Testnet.Process.Run
+import qualified Testnet.Property.Utils as H
+import           Testnet.Runtime
+
+import           Hedgehog (Property, (===))
+import qualified Hedgehog.Extras.Stock.IO.Network.Sprocket as IO
+import qualified Hedgehog.Extras.Test.Base as H
+import qualified Hedgehog.Extras.Test.File as H
+
+hprop_repeated_certificates_in_transaction :: Property
+hprop_repeated_certificates_in_transaction = H.integrationRetryWorkspace 0 "repeated-certificates-in-tx" $ \tempAbsBasePath' -> do
+  H.note_ SYS.os
+  conf@Conf { tempAbsPath } <- mkConf tempAbsBasePath'
+  let tempAbsPath' = unTmpAbsPath tempAbsPath
+  work <- H.createDirectoryIfMissing $ tempAbsPath' </> "work"
+
+  let
+    sbe = ShelleyBasedEraBabbage
+    era = AnyCardanoEra $ toCardanoEra sbe
+    eraString = anyEraToString era
+
+    tempBaseAbsPath = makeTmpBaseAbsPath $ TmpAbsolutePath tempAbsPath'
+    options = cardanoDefaultTestnetOptions
+      { cardanoNodeEra = era
+      }
+
+  TestnetRuntime
+    { configurationFile
+    , testnetMagic
+    , poolNodes
+    , wallets=wallet0:wallet1:_
+    } <- cardanoTestnetDefault options conf
+
+  poolNode1 <- H.headM poolNodes
+  poolSprocket1 <- H.noteShow $ nodeSprocket $ poolRuntime poolNode1
+  execConfig <- H.mkExecConfig tempBaseAbsPath poolSprocket1 testnetMagic
+
+  let socketName' = IO.sprocketName poolSprocket1
+      socketBase = IO.sprocketBase poolSprocket1 -- /tmp
+      socketPath = socketBase </> socketName'
+  epochStateView <- getEpochStateView (File configurationFile) (File socketPath)
+
+
+  let testStakeDelegator = work </> "test-delegator"
+
+  H.createDirectoryIfMissing_ testStakeDelegator
+  let testDelegatorVkeyFp = testStakeDelegator </> "test-delegator.vkey"
+      testDelegatorSKeyFp = testStakeDelegator </> "test-delegator.skey"
+      testDelegatorPaymentVKeyFp = testStakeDelegator </> "test-delegator-payment.vkey"
+      testDelegatorPaymentSKeyFp = testStakeDelegator </> "test-delegator-payment.skey"
+      testDelegatorRegCertFp = testStakeDelegator </> "test-delegator.regcert"
+      testDelegatorDeregCertFp = testStakeDelegator </> "test-delegator.deregcert"
+
+  _ <- cliStakeAddressKeyGen work
+    $ KeyNames testDelegatorVkeyFp testDelegatorSKeyFp
+  _ <- cliAddressKeyGen work
+    $ KeyNames testDelegatorPaymentVKeyFp testDelegatorPaymentSKeyFp
+
+  testDelegatorPaymentAddr <- execCli
+                [ "address", "build"
+                , "--testnet-magic", show @Int testnetMagic
+                , "--payment-verification-key-file", testDelegatorPaymentVKeyFp
+                , "--stake-verification-key-file", testDelegatorVkeyFp
+                ]
+
+  -- Test stake address registration cert
+  createStakeKeyRegistrationCertificate
+    tempAbsPath
+    era
+    testDelegatorVkeyFp
+    2_000_000
+    testDelegatorRegCertFp
+
+  createStakeKeyDeregistrationCertificate
+    tempAbsPath
+    era
+    testDelegatorVkeyFp
+    2_000_000
+    testDelegatorDeregCertFp
+
+  txin1 <- findLargestUtxoForPaymentKey epochStateView sbe wallet0
+  multipleCertTxBodyFp <- H.note $ work </> "registration.txbody"
+  void $ execCli' execConfig
+    [ eraString
+    , "transaction", "build"
+    , "--change-address", testDelegatorPaymentAddr
+    , "--tx-in", Text.unpack $ renderTxIn txin1
+    , "--tx-out", Text.unpack (paymentKeyInfoAddr wallet1) <> "+" <> show @Int 5_000_000
+    , "--witness-override", show @Int 2
+    , "--certificate-file", testDelegatorRegCertFp
+    , "--certificate-file", testDelegatorDeregCertFp
+    , "--certificate-file", testDelegatorRegCertFp
+    , "--certificate-file", testDelegatorDeregCertFp
+    , "--certificate-file", testDelegatorRegCertFp
+    , "--out-file", multipleCertTxBodyFp
+    ]
+
+  txJson <- (H.leftFail . A.eitherDecode @A.Value . fromString) =<< H.execCli
+    ["transaction", "view"
+    , "--tx-file", multipleCertTxBodyFp
+    ]
+  A.Success certificates <- fmap (A.fromJSON @[A.Value]) . H.nothingFail $ txJson ^? L.key "certificates"
+  H.noteShow_ $ A.encode certificates
+  length certificates === 5
+
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/StakeSnapshot.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/StakeSnapshot.hs
index a115589db66..8f3cdf289f8 100644
--- a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/StakeSnapshot.hs
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/Conway/StakeSnapshot.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
-{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
-
 module Cardano.Testnet.Test.Cli.Conway.StakeSnapshot
   ( hprop_stakeSnapshot
   ) where
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/KesPeriodInfo.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/KesPeriodInfo.hs
index cc7c7c90e91..24b67202fb7 100644
--- a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/KesPeriodInfo.hs
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/Cli/KesPeriodInfo.hs
@@ -127,6 +127,7 @@ hprop_kes_period_info = H.integrationRetryWorkspace 2 "kes-period-info" $ \tempA
     tempAbsPath
     (cardanoNodeEra cTestnetOptions)
     testDelegatorVkeyFp
+    2_000_000
     testDelegatorRegCertFp
 
   -- Test stake address deleg  cert
@@ -153,12 +154,12 @@ hprop_kes_period_info = H.integrationRetryWorkspace 2 "kes-period-info" $ \tempA
   UTxO utxo2 <- H.noteShowM $ decodeEraUTxO sbe utxo2Json
   txin2 <- H.noteShow =<< H.headM (Map.keys utxo2)
 
-  let eraFlag = convertToEraFlag $ cardanoNodeEra cTestnetOptions
+  let eraString = anyEraToString $ cardanoNodeEra cTestnetOptions
       delegRegTestDelegatorTxBodyFp = work </> "deleg-register-test-delegator.txbody"
 
   void $ execCli' execConfig
-    [ "transaction", "build"
-    , eraFlag
+    [ eraString
+    , "transaction", "build"
     , "--change-address", testDelegatorPaymentAddr -- NB: A large balance ends up at our test delegator's address
     , "--tx-in", Text.unpack $ renderTxIn txin2
     , "--tx-out", utxoAddr <> "+" <> show @Int 5_000_000
diff --git a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/LedgerEvents/Gov/InfoAction.hs b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/LedgerEvents/Gov/InfoAction.hs
index aaaaae4e847..9b9e132af7e 100644
--- a/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/LedgerEvents/Gov/InfoAction.hs
+++ b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/LedgerEvents/Gov/InfoAction.hs
@@ -8,13 +8,6 @@
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
 
-#if __GLASGOW_HASKELL__ >= 908
--- Data.List has a lot of partial functions and GHC >= 9.8 warns about these.
-{-# OPTIONS_GHC -Wno-x-partial #-}
-#endif
-
-{- HLINT ignore "Use head" -}
-
 module Cardano.Testnet.Test.LedgerEvents.Gov.InfoAction
   ( hprop_ledger_events_info_action
   ) where
@@ -72,7 +65,7 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
   testnetRuntime@TestnetRuntime
     { testnetMagic
     , poolNodes
-    , wallets
+    , wallets=wallet0:wallet1:_
     , configurationFile
     }
     <- cardanoTestnetDefault fastTestnetOptions conf
@@ -132,16 +125,16 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
        ]
 
   -- Retrieve UTxOs for registration submission
-  txin1 <- findLargestUtxoForPaymentKey epochStateView sbe $ wallets !! 0
+  txin1 <- findLargestUtxoForPaymentKey epochStateView sbe wallet0
 
   drepRegTxbodyFp <- H.note $ work </> "drep.registration.txbody"
   drepRegTxSignedFp <- H.note $ work </> "drep.registration.tx"
 
   void $ H.execCli' execConfig
     [ "conway", "transaction", "build"
-    , "--change-address", Text.unpack $ paymentKeyInfoAddr $ wallets !! 0
+    , "--change-address", Text.unpack $ paymentKeyInfoAddr wallet0
     , "--tx-in", Text.unpack $ renderTxIn txin1
-    , "--tx-out", Text.unpack (paymentKeyInfoAddr (wallets !! 1)) <> "+" <> show @Int 5_000_000
+    , "--tx-out", Text.unpack (paymentKeyInfoAddr wallet1) <> "+" <> show @Int 5_000_000
     , "--certificate-file", drepCertFile 1
     , "--certificate-file", drepCertFile 2
     , "--certificate-file", drepCertFile 3
@@ -152,7 +145,7 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
   void $ H.execCli' execConfig
     [ "conway", "transaction", "sign"
     , "--tx-body-file", drepRegTxbodyFp
-    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair $ wallets !! 0
+    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair wallet0
     , "--signing-key-file", drepSKeyFp 1
     , "--signing-key-file", drepSKeyFp 2
     , "--signing-key-file", drepSKeyFp 3
@@ -179,13 +172,13 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
   txbodyFp <- H.note $ work </> "tx.body"
   txbodySignedFp <- H.note $ work </> "tx.body.signed"
 
-  txin2 <- findLargestUtxoForPaymentKey epochStateView sbe $ wallets !! 1
+  txin2 <- findLargestUtxoForPaymentKey epochStateView sbe wallet1
 
   H.noteM_ $ H.execCli' execConfig
     [ "conway", "transaction", "build"
-    , "--change-address", Text.unpack $ paymentKeyInfoAddr $ wallets !! 1
+    , "--change-address", Text.unpack $ paymentKeyInfoAddr wallet1
     , "--tx-in", Text.unpack $ renderTxIn txin2
-    , "--tx-out", Text.unpack (paymentKeyInfoAddr (wallets !! 0)) <> "+" <> show @Int 5_000_000
+    , "--tx-out", Text.unpack (paymentKeyInfoAddr wallet0) <> "+" <> show @Int 5_000_000
     , "--proposal-file", infoActionFp
     , "--out-file", txbodyFp
     ]
@@ -193,7 +186,7 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
   void $ H.execCli' execConfig
     [ "conway", "transaction", "sign"
     , "--tx-body-file", txbodyFp
-    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair $ wallets !! 1
+    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair wallet1
     , "--out-file", txbodySignedFp
     ]
 
@@ -238,7 +231,7 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
       ]
 
   -- We need more UTxOs
-  txin3 <- findLargestUtxoForPaymentKey epochStateView sbe $ wallets !! 0
+  txin3 <- findLargestUtxoForPaymentKey epochStateView sbe wallet0
 
   voteTxFp <- H.note $ work </> gov </> "vote.tx"
   voteTxBodyFp <- H.note $ work </> gov </> "vote.txbody"
@@ -246,9 +239,9 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
   -- Submit votes
   void $ H.execCli' execConfig
     [ "conway", "transaction", "build"
-    , "--change-address", Text.unpack $ paymentKeyInfoAddr $ wallets !! 0
+    , "--change-address", Text.unpack $ paymentKeyInfoAddr wallet0
     , "--tx-in", Text.unpack $ renderTxIn txin3
-    , "--tx-out", Text.unpack (paymentKeyInfoAddr (wallets !! 1)) <> "+" <> show @Int 3_000_000
+    , "--tx-out", Text.unpack (paymentKeyInfoAddr wallet1) <> "+" <> show @Int 3_000_000
     , "--vote-file", voteFp 1
     , "--vote-file", voteFp 2
     , "--vote-file", voteFp 3
@@ -260,7 +253,7 @@ hprop_ledger_events_info_action = H.integrationRetryWorkspace 0 "info-hash" $ \t
   void $ H.execCli' execConfig
     [ "conway", "transaction", "sign"
     , "--tx-body-file", voteTxBodyFp
-    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair $ wallets !! 0
+    , "--signing-key-file", paymentSKey $ paymentKeyInfoPair wallet0
     , "--signing-key-file", drepSKeyFp 1
     , "--signing-key-file", drepSKeyFp 2
     , "--signing-key-file", drepSKeyFp 3
@@ -297,9 +290,9 @@ foldBlocksCheckProposalWasSubmitted
   -> IO (Maybe LedgerEvent, FoldStatus) -- ^ Accumulator at block i and fold status
 foldBlocksCheckProposalWasSubmitted txid _ _ allEvents _ _ = do
   let newGovProposal = filter (filterNewGovProposals txid) allEvents
-  if null newGovProposal
-  then return (Nothing, ContinueFold)
-  else return (Just $ newGovProposal !! 0, StopFold)
+  pure $ case newGovProposal of
+    [] -> (Nothing, ContinueFold)
+    proposal:_ -> (Just proposal, StopFold)
 
 
 retrieveGovernanceActionIndex
diff --git a/cardano-testnet/test/cardano-testnet-test/cardano-testnet-test.hs b/cardano-testnet/test/cardano-testnet-test/cardano-testnet-test.hs
index 7870e463193..762402b3d42 100644
--- a/cardano-testnet/test/cardano-testnet-test/cardano-testnet-test.hs
+++ b/cardano-testnet/test/cardano-testnet-test/cardano-testnet-test.hs
@@ -10,6 +10,7 @@ import qualified Cardano.Testnet.Test.Cli.Babbage.StakeSnapshot
 import qualified Cardano.Testnet.Test.Cli.Babbage.Transaction
 import qualified Cardano.Testnet.Test.Cli.Conway.DRepRetirement as DRepRetirement
 import qualified Cardano.Testnet.Test.Cli.Conway.Plutus
+import qualified Cardano.Testnet.Test.Cli.Conway.RepeatedCertificatesInTransaction
 import qualified Cardano.Testnet.Test.Cli.KesPeriodInfo
 import qualified Cardano.Testnet.Test.Cli.Queries
 import qualified Cardano.Testnet.Test.Cli.QuerySlotNumber
@@ -62,11 +63,11 @@ tests = do
               [ H.ignoreOnMacAndWindows "leadership-schedule" Cardano.Testnet.Test.Cli.Babbage.LeadershipSchedule.hprop_leadershipSchedule -- FAILS
               , H.ignoreOnWindows "stake-snapshot" Cardano.Testnet.Test.Cli.Babbage.StakeSnapshot.hprop_stakeSnapshot
               , H.ignoreOnWindows "transaction" Cardano.Testnet.Test.Cli.Babbage.Transaction.hprop_transaction
+              , H.ignoreOnWindows "repeated-certificates-in-tx" Cardano.Testnet.Test.Cli.Conway.RepeatedCertificatesInTransaction.hprop_repeated_certificates_in_transaction
               ]
           -- TODO: Conway -  Re-enable when create-staked is working in conway again
-          --, testGroup "Conway"
+          -- , testGroup "Conway"
           --  [ H.ignoreOnWindows "stake-snapshot" Cardano.Testnet.Test.Cli.Conway.StakeSnapshot.hprop_stakeSnapshot
-          --  ]
             -- Ignored on Windows due to <stdout>: commitBuffer: invalid argument (invalid character)
             -- as a result of the kes-period-info output to stdout.
           , H.ignoreOnWindows "kes-period-info" Cardano.Testnet.Test.Cli.KesPeriodInfo.hprop_kes_period_info