I suggest adding a warning to the "Turbo" option to prevent bug reports, something like "Turbo (hack, causes glitches)".
Some people don't realize that this is a system altering hack and it WILL change how the game supposed to run.
Also, it would be a good idea to not save the Turbo option after core reset, default should always be Disable.
Unless of course you want a million bug reports with Turbo On.
SuperFX Speed and CPU Turbo can be together at the bottom of the menu, since they are hacks.