Yes if you burn a gamecube game to a disc, then install a patched mios to v8 and enable wii back up launching then yes it will work. But it won't work through USB.
What's the appropriate extension for a gamecube game? Is it .gcm? So I just burn the game to any DVD, and install mios.... is there a topic that explains this procedure?
I'm not a coder or a hacker or anything so I don't know much about this, but what's stopping someone from using MINI to code a custom gamecube mode that doesn't turn off the USB support?