Interesting. I am not finished investigating, but it is worth pointing out that
A$=DIALOG("","%"+CHR$(279))will crash the 3DS, resetting it. EDIT: Some more values that cause crashes: 285, 298, 311, 324, 337, 350 (at this point I stopped testing numbers in steps of 13), 473, 474, 475 (and I have stopped testing altogether here).