What I can't quite understand is what do you want to test that isn't known already, other than if the forwarder works or not.
Wii U's vWii is just like the original Wii console: same limitations, same speed. All FX games are playable, some with some mild frame skipping, which is handled very well by the emulator, specially if you add some "FX overclock". I'm a super Star Fox fan and have played it to death on every single console that can be emulated, just for fun, to check how tolerable the experience is.
Wii U's vWii "overclocking" is just a "Wii" with the full Wii U CPU speed. Everyone using it already knows it gives more room for emulators to reach full speed on heavy games. In this case I purposefully added new FX speed options (which you should know as you already copy-pasted those into Snes9x GX's commits) because the Wii U can handle it without problems. Doom is specially benefited from this, giving it a much fluid experience, not accurate to the original of course since you're altering the game, but a new way to play it indeed. Those were personally tested before I even committed the changes to my GitHub.
So, other than testing if the forwarder works, is there any new or not known info that you really need? Send me the installer plus all the files configured that you want to know if they work, to drop them in the SD.