Before reading: I have an M3 Simply and love it to pieces. Also have a GnM which I bought before the M3.
Now, maybe I`m just a little nutty, but I got an idea. What if it were possible to dump the ROM of the M3 Simply, set up the MicroSD card the way the Simply needs it (menu.dat, etc), and then run the rom through Games n Music? So it`d be like: boot Games n Music> run M3 Simply.nds> run ROM.
Crazy enough to work? Or silly noob-ish crackpot theory? You be the judge