I think Gale conversation have the problem that they seem to have low priority in the camping talks queue. So out of curiosity I've run a quick test with spamming rest on patch 5. Basically, every time Gale's approval changed I'd hit long rest until he got a camp scene. No adventuring in-between. On medium approval Shadowheart got two talks, Laezel got two, Wyll and Astarion got one before Gale got his weave scene. I eventually got all the dialogues, including the romantic talks, out if him that way. I guess if someone wants the most Gale content without chilling at the camp all the time, they'd have travel with him alone.
That's what I discovered as well. If you travel with additional companions, you will have to see all their scenes up to that point in the game before Gale's scenes will play out. But it does also feel like the farther you get in the game, the more it feels like his weave scene will never occur after a certain point. That's why I don't leave the grove till I get it.
