Small note / update: I made a little woopsy on the build uploaded yesterday, the music-timer script wasn't triggering properly, so that's been fixed. Playing through it without the music felt off, and at first I thought "heck it", but I do think it adds something to the experience.
I also had a bit of a eureka moment regarding enemy behaviour - they were prone to running into doors and barricades and just standing around, not trying to break down the barricades. I realized that their OnTriggerEnter function was only firing once, and subsequent fires were the result of their anti-flocking behaviour. I've instead put timers on their triggers to enable and disable every half second or so, so new Trigger events get called. It seems to be almost identically performant, and far more performant than OnTriggerStay (Im quite frankly scared to even use TriggerStay anymore, atleast in the ways I was originally using it).
TL,DR: The build now has some cool tunes working, and the enemies are MUCH better at getting to you. Cheers!