It's not possible to deploy an SPFx to the site collection App catalog when the number of Trusted Script Sources in Content Security Policy is too large (in our case, it was 582).
It doesn't work with Add-PnPApp (Add-PnPApp -Path ./myapp.sppkg -Scope Site -Publish)
or with ALM PnP. => The app is added to the Site Collection App Catalog, but the status remains Deployed = No.
The error is - "Value of: [CSPConfig] cannot exceed: [100000]."

I would expect that command to work well in the scope of site collection. It should not take into account script sources from other site collections. (Trusted Script Sources on tenant level)

I'm using Windows operating system with PSVersion 7.5.3 and PnP.PowerShell 3.1.0 version.

Please check also related issues - SharePoint/sp-dev-docs#10412, SharePoint/sp-dev-docs#10369