He can still be vocal in the councils of the Valar. Just because Tolkien doesn't tell us what he had to say doesn't mean we can't show it.
I mean I think he could watch them in secret, I don't think Melkor (or Mairon) should interact with the elves by entering the group and talk to them at this point. Maybe they could sneak up to one or two elves and whisper ideas in their heads without being seen.I think it is a powerful image, but I'm not sure where to include it. At this point, I see it coming up as a flashback, perhaps after Melkor is released or during the SuperSecretNecromanticOrcProject in Angband.
(For those following along at home, this is discussed around 18:50-20:55 of Part 3 of the videos above.)
Perhaps we can use some voiceover on these scenes.6. First pinch point
Earthquake, lightning, panic. The Teleri are terrified ('The Sky is Falling!'). The Noldor accept their fate (We've had a good run, but it's over now.) The Vanyar have Estel (There's nothing we can do about this, but let's trust it will turn out okay). We have the point of view of young Celeborn (possibly with voiceover).
Early battle. There are very remote sounds and flashes from the battle at Utumno. [The viewer should recognize events such the arrival of Eonwë by lighting bolt from Season 1 Episode 13.] The elves abandon some of their houses and build more defensive (underground?) hideouts.
8. Mid point
Lull, fire across the lake. As time progresses, the battle seems to die down. In the lull, the elves wonder...is it over? And then...it is closer! Fire in the trees across the Lake, sounds of battle.
Evacuation to Vanyar island. The elves decide to evacuate to the island of the Vanyar (using simple ferry boats).
10. Second pinch point
Fire in the sky, discussion of abandoning Cuiviénen. [Some run off into the woods, never to be seen again?] They watch the fires spread around the Lake.
The battle's anticlimax. It quiets down. A rainstorm comes up and puts out the fires. There is confusion on the part of the elves....is it really over now? Rebuild and return to life as normal (though still on the Island).
Yes I agree, but we might push it even further. For instance, what is Ingwë's opinion on this:I do think that showing Ingwë at the head of the Vanyar contingent in the first council will illustrate his position in their society.
I think we can add that Elwë could be one of those in favour of the diaspora plan. Ingwë might not be so sure. He might say that they are born here at Cuiviénen, and as long as there is no clear sign that this is the wrong place to be, the best thing might be to stay. He might argue that he has been thinking about the Rider (not the Hunter) and thinks that there's something important about that being. Perhaps Oromë enters in the middle of such a conversation, even.12. Second plot point
Establish diaspora plan. The elves do not intend to stay in one place, but to explore the many unknown places of the world. They are preparing their boats and having a feast and song to celebrate 'Hey we're still alive!' [This is meant as a farewell feast for the elves who are leaving the island.]