So, I was walking my dog (not Solas, my real-life dog who doesn't leave me even though she loves me...) and I had a little thought.
I don't think we're done with the eluvians yet. TME set them up quite a bit, we never got to explore the crossroads etc. I felt it was going to be more important... Then I thought: Every eluvian has a specific key. The eluvians where how the vast elven empire held together by making traveling easy. Fen'harel was said to move among both the gods and the forgotten ones, beings I doubt wanted to be close to each other. The anchor, which comes from the orb, is likened to a key many times.
What if, and I realize this might be a big stretch, the anchor could be a sort of master key for all eluvians? The purpose of restoring the foci would be to regain the key, which in turn would restore the remaining eluvians regardless of their unique key. It could even be Solas' MO ("They sleep, masked in a mirror, hiding, hurting, and to wake them...").
Or maybe I'm trying to headcannon a way for my non-mage Lavellan to still be able to chase after Solas grumble grumble...