Sorry for the radio silence, I've been working on things that are hard to appreciate in a video.
I've redone the script editor and identified over a hundred functions that are called from the script bytecode. It's quite readable now. It was tricky, but the script dumper now works with the dissembler to recognize jump tables and pseudo instructions and handle them properly. This means that it is now possible to edit cutscenes (and even construct your own) in addition to having full control over important data structures. As proof, here is another simple video:https://www.youtube.com/watch?v=bN62tiNEUj8
This is a demonstration of custom NPCs, both friendly and hostile. It also includes custom text, custom battle formations, and loading enemies imported from other portions of the game (Clubba is not supposed to be loaded for battles in Koopa Bros fortress). It is now possible to add NPCs wherever you like, including field enemies.
This editor will release along with a complete example mod and the source files needed to build it. As a bonus, check out the custom game logo at the start of the video (the name is temporary).