Update: I picked up my SD2SNES yesterday from the Post Office. Haven't tested it yet though. The black SNES cart shell looks like it was made with a 3D printer to be honest and is less than stellar looking, but the cuts at the top for the full-sized SD slot and miniUSB are perfect. You're better off buying microSD cards these days though so they can fit in anything and as they include the adapter to make them a full-sized SD card. The miniUSB slot is if you don't have a SD slot on your PC, you can plug a male miniUSB to USB cable to load up the SD card directly with the flashcart. Your tablet or phone will have microSD, so you can load all the ROMs there, then with the SD adapter plug it in to the flashcart if you don't have these old miniUSB cables (that's the bigger size, not micro like your phone).
Anyway, will report back when I get to test it.