Okay guys i managed to fix the issue with the festival map crashing the game and ramping up cpu/ram usage.
The main crash source is Event EV005 (id 5), page 1: it repeatedly runs Play BGM (code 241) and Play BGS (code 245) in a Parallel Process loop with no Wait, which can spam audio restarts/loads
I basically just did a crap edit of Map022.json and fixed the problem, now it doesn't play music on the map anymore.