Flashing older firmware on a bad-S/N switch is an instant no-no, but what about downgrading GAMES? I'd assume digital ones are also a no-no, but the cartridge data is permanently written on a ROM with no way to rewrite, so there's no way the Switch could write update data to the cartridge.
(damn, if only an exploit was found for units with the bad S/N...)
(damn, if only an exploit was found for units with the bad S/N...)