I've spotted what could potentially be a huge bug in the FR version of the hack. I'm not 100% certain exactly what it actually breaks, but it breaks something.
I can confirm that it completely breaks the functionality of Blaze, Torrent, Overgrow and probably (although I have yet to see the check itself) Swarm. It also breaks some sort of check which would normally halve the amount of damage dealt for certain types of attack under certain circumstances.
To see evidence for yourself, go to 0x3F102. You will see there are a bunch of type based checks, which read the category byte kept in R9. Under normal circumstances, the game will check the type, and if it matches, will branch link to 0x19F18, passing 0xE in R0, 0x0 in R1, 0x0 in R2 and a changeable byte (seems to depend on the type) in R3. What this checks and returns, I do not know.
However, due to the split changes implemented, none of these checks ever pass, and as such, whatever this piece of functionality is, as well as the abilities named above, simply do not work.