I just completed Paruddma's Maw. Incredible work, really, I really enjoyed the whole quest in Aimrah (first time I've played that one) and the dungeon itself.

I think there could be just a couple additions at some points of the related quests

Tynachos directed me to Aimrah with "The Creature in the Lake's Soul" quest, the locals there informed me about the local priest looking for his friend.

I played thourgh the whole quest, while also looking for hints about the location of Paruddma's Maw. The only clue I found was in the book Notes on Dreugh, entry 14 reads that the dreugh come from the abyss far in the south.

I might've missed some other clue during the quest but If the book is the only thing pointing to Paruddma's Maw location, I think that the journal should be updated with that small hint, just in case some player doesn't read it till the end or skims the relevant bit.

After completing the dungeon, there's no new dialogue with Zadathys Aldrethi to inform him about your meeting Paruddma. I think he might be interested in hearing what went down in there.

Less importantly, Anara Marvus might want to hear about that too, especially if you told her the truth at the end of Aimrah's quest.

I still have to track down the priest, if that's even possible, but in that case he might be interested too.

That's all, let me tell you again, impressive work on both the quest and the dungeon.