The main 2 reasons behind purchasing a Supercard DSTwo is for great compatibility with the newest DS firmwares, and playing backwards GameBoy games.
When you first purchase the Supercard DSTwo you might install the NOSGBA plugin and set it up the same as an R2 with Lameboy. DON’T DO IT! They’re slow and offer minimum features.
GameBoy Advance Setup
First, get and install the TempGBA package. This will offer more features and better speeds. As well as actually saving the system settings.
GameBoy Color Setup
Second, get and install the GameYob software. This is 10x better than Lameboy. It’s even still being worked on today.