I had no idea the crucible was even usable for that, wasn't telegraphed at all. I found the buff/debuff to be infuriatingly inconsistent and eventually the lava mechanic just broke altogether and the only way to leave that zone was to fast travel out of it, and I could never return.

I don't disagree with your stance, but I am curious why you decided on a trainer instead of picking the easier difficulty. Did you try it and still find it too much? I have read about the differences between modes but haven't actually tried anything other than normal, and even though I'm extremely familiar with PF 1e and D&D 5e I've struggled with lots of encounters.