I think the Well of Dreams Finale is well-designed. I have one suggestion that I think would improve coordination without trivializing the finale.
TL;DR
- Place objective markers on shields with symbols and the associated tome. Have the markers disappear once they’re matched - and allow the markers to re-appear if they become un-matched.
IIRC, this is already done on maps like Festering Ground, where un-popped buboes become marked after some time has passed.