OK, so I fired the mod up again this morning to see what's what. I don't know how much sense this is going to make, but here goes...
As I said in my previous-to-last post, I was stuck at a loading screen at 100% when I entered Champs Arena. So I quit the game to restart. I double checked the platinmods.txt file or whatever it's called and ensured that the extra damage modifier was disabled, which it was. I loaded the game this morning and despite the setting being disabled, high damage was still occurring. Now, I didn't receive an "unusual gameplay detected" error right away, but when I went up against a player for eight points that had low-level threat defensive teams, then and only then, did that error message pop up.
So I thought, alright fine, I'll stick to teams with defensive teams with a higher threat level. So, I found the same player from last night, the one whose loading screen I was stuck on? Yeah, happened again; 100%, did not load.
I realize that all sounds bizarre but I swear that's what's happened.