No nothing really new, I've been far too busy, and I'm also working on another project.
The problem is that the GBA can only have a set number of OW palettes at a time.
Due to this, all of the palettes are loaded at the game's start-up.
The only way to use a new palette is to overwrite one in the RAM.
You would have to hack the games engine (using ASM) to dynamically replace unused OW palettes with the ones on the map.
While this can be done, it would be very difficult.