Luckily a new tester has come forward (and one that has recently re-completed parts I and II), and may be giving things a semi-final runthrough this week. I'd love to expose any potential problems or unfinished aspects before I seal it all up.
I do know I have to complete some companion chatter for both Malcarus and Anziath, and I may want to go back and add one more triggered encounter in the late plot discovery. I think there is a bit too much fact-finding and not enough violence right before the final series of sequences so I may try to mix things up a bit there.
In the meantime, here are some shots of dimensional ruins after I spent an evening tinkering with placed effects and environmental settings:
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