For this case: This was prob around the 5-6 cross so it can happen whenever. The brute did indeed die on a PB at the same time as i picked up the cross. Infact we both had the exact same amount of tiles to walk for our destination (1 tile, i like to set it up this way since it lets you keep the PB tile, my guess is that this is because the boss wont remove the tile since it think there is a heretic on it). No sounds, i play with it of but will turn in on to get information. The heretic died via smite and as far as i can recall no warping through him was taking place. There was prob a gem on the tile since my deck mostly consisted of those. I did not activate any potions.
I think generally most of these things can be said about the bug. it has happend 3-4 times i think. Most of the times PB was involed i think. Generally i have also found some other inconsistencies regarding heretics and brutes. Sometimes they wont move if the board is cleared during the same brickplacement etc. This last paragraph might not be fully accurate since it happend a while ago.
Turning of heretics might indeed be a good idea. It will only affect better players since this only matters after 3rd boss and beyond so the impact is not to huge perhaps. If you need help testing (and if there is a way to organise that) i will gladly help. I love knowing all of the little interesting intricacies of this game.
Side question. After consuming 4-5 Chaos six packs (trying to get another DD potion) they stopped appearing in chests yet vednors still sold them. Is there a cap here as well or just RNG?
Also i would love if you changed is so that the game starts writes say 1.3 T instead of 1300 G. It makes is feel so much nicer hitting that new barrier and seeing that new letter lol (for me this is since i wanna see the Quadrillion symbol as fast as possible lol,)
Edit: If you are going to remove heretic spawns in bosses, please do as fast as possible. Wanna get back to grinding for 1 Quad as fast as possible lol :D