I feel like this is kind of a long shot, but is there a way to make proposition rewards have an effect on your units or something like that? IE: Treasure X adds extra Y amount of bonus gil from battles... Treasure Z adds +1 PA to all units?
This data is readily available at all times from http://ffhacktics.com/instructions.php?id=B0 (http://ffhacktics.com/instructions.php?id=B0). However, you will have to ASM it, as it's a bit out of the ordinary even for something like ALMA.
So if i'm understanding you correctly, you can use an event to make assign changes to the proposition rewards within the game's parameters? But any other custom changes would have to be ASM'd? Forgive me as I haven't gotten into researching event editing yet, but can you make backround changes without going into a Map with sprites and all; can you simply make the event occur when you obtain the proposition rewards?