I'm looking to buy a slot-2 cart and would like to know if it supports fully-featured integration with my Supercard DS One. Is it possible to launch a GBA game from the Supercard GUI and actually save the games?
The SCDS only has native support for the slot-2 Supercard products. However, these aren't that good at GBA gaming in the first place, and if you launch the *.gba game from the SCDS menu, you won't be able to save the game. If you want to get a 3in1 and use GBA ExpLoader, you can do that, as it will work just as well as it would on any other device.