There's a bunch of leaked watchdogs builds that have symbols included, probably not wii u builds but I'd guess things would transfer over.
Those would give you function names for the game code which should make it much easier to look into, then you can find whatever funcs need to be patched.
WiiU patches aren't too hard to make neither, grab a copy of ghidra/ida and get to work OP.
(or just do
>>715049668, you could offer like $50 on gbatemp/discord and some kid would probably pick it up)