Please don't alter the $2101, just read the value written there, particularly bits 5-7 (sets Sprite size).
Post the code here, so we can delve in details. Keep in mind that reading/writing to video could be auto-incremented. So even if you have initial value in the address ($2116), if you have some read/writes ($2118/$2139) after initialization and the code you are looking, the address has been already changed! Besides as I said the transfer could be done trough DMA/HDMA ... it all depends.
You know what? Lets do something else:
- Download vSNES (the tool I've talk about)
- Make sure you use zSNES as emulator. Load the ROM and when the namingway screen pops up - make a savestate
- Send me or attach here that savestate
* You can check for yourself many things in vSNES - like what mode you use, layers, tiles, sprites,...
