There's no easy fix to this, but something does need to be done to fix this. However, it isn't something you can fix without reworking the entire dungeon into either a solo instance or rewriting the entire story of the area. Castrum is just way too long. I did it a few times at first, but after a few times, I just stopped doing it because I didn't have time for it in the day. On top of that, it just isn't worth it, even if you do somehow get 500+ poetics for it. I was able to finish entire episodes of TV shows on Netflix over the course of a run.