Native GCN support on the mini is a hardware issue, not software. MIOS and all the rest of it are there, but the drive rejects GCN discs and the ports and memory card slots aren't soldered to the board. Getting
Nintendont to work (since it does literally the exact
opposite of backwards compatibility in providing a compatibility layer to make GameCube games
forwards compatible with the Wii) would just be a matter of installing a custom channel (the Homebrew Channel) with AHBPROT disabled - the mini already uses IOS 58 (Unless I'm so wrong that I may as well burn my power user hat), has a USB port, and Bluetooth support.