I'm not sure if this is much help to you, but if you look for Yoshifanatic's disassembly, you could make the All Stars version of SMB2 a stand alone game without losing the ability to save the game, so if you want to hack SMB2 but you specifically want to hack the SNES version, that might be something to consider. Same thing goes for any of the SMAS games really, but I wouldn't recommend it for SMB1 or TLL until someone can get the brick physics patch working for the disassembled games without them crashing.
PERFECT. Thanks for the heads up about disassembly. I will definitely check that out. I'll see what I can do about hacking the a standalone SNES SMB2