I think I have pinpointed what bothers me about Thingol in this episode.
This entire season has been about reconciliation of grievances, and the Sindar-Noldor storyline focused very much on Thingol's reaction to news of the kinslaying. This wedding is the first/only time Thingol is going to the meet the Noldor who aren't House of Finarfin in person.
Thingol is a guest of Finrod (not the other way around, so there is a role-reversal there. We should play with that a bit). And Thingol is introduced to two actual kinslayers - Fingolfin and Maedhros. And he, what, nods politely? I get it - it's Galadriel and Celeborn's wedding, everyone's on good behavior, no one wants to cause a scene. But...but...seriously, nothing happens at all?
I certainly enjoy the conversation between Fingolfin and Thingol about Cuivienen. I guess I am just asking for some more tension beyond Maedhros and Thingol essentially greeting each other casually. He need to make better use of this meeting.