Genesis Plus GX Debugger has VDP Register viewer ported right from the Exodus emulator, and they actually work, despite having different code languages. Most of VDP Registers are just visual effects, and will not affect TAS unless the game requries it for it to properly work. Hex Editor also has new memory domains such as 68K Regs and Z80 Regs, but this sometimes might be used for TASers to see if a desync occurs, or when you see that the game starts to behave weird. Now, in Dr. Robotnik's Mean Bean Machine, if you edit address 111D with bytes from 01 to 0F in 68K RAM, the VDP goes berserk, which might confuse you if you can't see the VDP Registers.