I just hit the opportunity to go on the final mission and I've been clearing up the old quest log, and I realized that Silena's quest The Thinking Construct appears to be stuck. I've cleared every other NPC quest fine, but this one seems to be hung up waiting for a trigger.
Basically, I saw the construct at the Rotting Border; talked to Silena about it; took her to check out the door, where she said she'd work on it; talked to Redbeard about the construct; talked to Silena about talking to Redbeard. The journal says something about how she's still working on the door and that I should check in with her occasionally, but there's nothing new in her dialogue tree and I'm about to hit endgame.
Full disclosure, I basically never used Silena in my party. Doubt that matters, because I did the same with Khalida and her quest fired just fine.
Any thoughts would be appreciated.