I came up with a plan for homebrew on all versions:

  1. Obtain dumps for 1.50 and 1.51
  2. Compare files (with file size, etc.) to attempt to find the file that had been patched in the 1.51 firmware to prevent homebrew
  3. Snag the unpatched file from the 1.50 firmware
  4. Create a program that "injects" it into a newer firmware via the TIFF or GTA Exploit

I will add RARs of the dumps tomorrow to this post (i am tired it is 12AM here). If you are curious about what I have found:

There is an additional font in the 1.51 firmware.

Two folders in the 1.51 firmware have smaller file sizes than the same two in 1.50.

Respond if anyone finds anything.