There's a ton of info that bloated the display script, so I moved it all to a separate file for HPCS GBC. Works with the script on the 1st post for this game.
#638856191736840479 - Harry Potter GBC Chamber of Secrets Final boss warp
Emulator used: Bizhawk 2.10
Skips to the final boss using the select bug, but as of now, slower than just going to an earlier story state, since it needs to wait 100k frames. Done in GBA player mode in hopes final run could be console verified.
Proof of concept of triggering the real final chapter ending, while in a completely different stage. In this case, stage 28, Go through the grand hall.
I managed to get a whole bunch of glitched items at once without crashing while attempting to improve the TAS. Posting here in case it might lead to something.