To address your reasons why Canoe should be ported in the more modern day...
1. That "lovely Nintendo interface" is in the process of being recreated, and the NES classic interface was already created for the switch with LaiNES and NESaliser support.
2. I can't speak on Canoe having less lag than snes9x, but snes9x is also not the only SNES emulator on switch, and there are more coming soon to address and fix its issues.
3. The patched games could be put on the switch, but there is no guarantee that they will work, as they may be dependent on certain hardware, like the SNES classic's hardware.
4. This requires Canoe not to be an emulator, but to be its own operating system entirely. This last one is completely improbable without porting the operating system itself to the switch.