Good thread!

It's nice and easy to have a multi boot, it's just a case of adding the NES/SNES nand image to your game list just as you would to add another rom, then once you select that 'game' it boots back up as the other console, really slick.

On my SNES mini I've got a NES & Super Famicom on there

Good guide by the creator here if anyone's interested