Short and sweet update this evening. I managed to set up the right triggers for a combat mode to be engaged when monsters were actively attacking the player, which switches the game from its normal mode into a different mode where things stop being "active" and switch into turn based activations (well, they don't do all that yet, but the mode is set up for them to do all that) - and I managed to get everything working again in terms of on-screen triggers and such when combat has finished.
So, overall, it's been very successful this evening. With some luck, tomorrow and over the weekend, I'll start to have some very rudimentary combat working. That's going to be super exciting - it's felt like this has been way too long in the coming.