Thanks, seems the new GSU detection routine doesn't affect speed
But i'd like someone to check this PR made to upstream Snes9x for add SuperFX 8MB ROM emulation support:
https://github.com/snes9xgit/snes9x/pull/712/files
And adapt it for be able to use this feature but with always avoiding overloading the Wii RAM/CPU for not make the games too slower.
I just don't know a simple way to do it. Maybe using a virtual memory for Wii? IDK.