I've got an older 3in1. To be specific, it's the hardware version before the 3in1 plus, and Moonshell 2 has always failed to detect it, no matter what I try.
I still live in hope that it's because of something small that I may have missed...
I've got pretty much everything else working with Moonshell 2: Soft reset, morning timer, image viewer, file deletion, heck, even loading GBA games... it all works just great, but Moonshell 2 always gives that damned "Extension memory was not found." message on startup.
If the 3in1 can be detected by Moonshell 2, I'd really appreciate it if somebody could give me a few pointers on how to get the two to play nicely together.