Are cranium rats and warrens of thought ever going to get fixed or will they require an unofficial mod?
The issues are the following:
1) Cranium rat spellcasting seems to work in such a way that there is one spellcasting rat and a lot of decoys who'll never spellcast. This "fails" a lot because:
- When the spellcasting rat isn't in a group of rats the rats are harmless - If you run into the spellcasting rat alone, there's a single rat casting spells at you (common in Warrens) - You can single out the spellcasting rat and prevent huge swarms of rats from spellcasting
2) If you deal with Many-as-one and the rats become non-hostile, getting them to become properly hostile again seems to be bugged.
This means that if you do Many-as-one's quest and retrun to loot the place, there will be a lot of passive Wererats and even Cranium Rat packs around. Often attacking one will not cause it's friends to help it.
3) If you go through the Warrens and kill everything, then go in and beat Many-as-One, when you exit his chamber the Wereras will respawn. This makes no sense, isn't like the rest of the catacombs and is very likely just a bug.
EDIT: For some reason the game also respawns ghouls every time you enter and exit Dead Nations which probably also shouln't be happening.
4) Wererat pathing seems to get them stuck a lot, and the Warrens room layout is such that they easily get stuck and do nothing.
This is because no 2.
5) The whole Warrens of Thought bussiness seems to be unfinished, it's clearly buggier than many other things, and seems disconected from the rest of the story (as well as unpopulated by things you can talk to). There are placeholder dialogues in the files which suggest this wasn't supposed to be the case, so some sort of fan restoration/integration could be made - but first the actually bugged stuff would have to get sorted out in the base game.