Good theory, I just tried this but unfortunately it did not work. The baddies reset but scripts did not.
You know what though, I'm going to make the best out of this and call it the better ending. This was the last quest for my party to complete and after killing Hawthorne they took out many members of the Empires Royal Guard showing the tenacity of Avernites. Isn't it canon that the heroes of Avernum just kinda disappear? Better to go out with a bang for your people instead of literally disappearing on the brink of war.
Regardless, thank you for the help!