In patch 9, I've tested this to see if it was the same, and yes, you can't get too high approval too fast (without long resting in between) or else you don't get the romance scene at the party. You have to get all the other scenes first, or at least to the weave scene, I'm guessing. I was testing that out, but ..
On another playthrough, I painstakingly made sure I didn't get his approval up quickly, took long rests, got the "go to hell" scene, waited to get the mirror scene, but made the mistake of getting Astarion's approval up a bit, which triggered a few scenes for him. Argh. Finally I decide to go down into the grove, at level 4, and save Arabella, without Gale there. Didn't matter, somehow I see "Gale approves" when I convince Kagha to let the girl go, even though he wasn't there. Sure enough, that brought me to medium approval and that effort was wasted. I could go back to a save before and just camp without saving Arabella. But it occurs to me this whole process has been ridiculous. It's like you have to do an immersion-breaking puzzle to get the wizard's romance to work. Do a puzzle to romance the wizard, haha. It doesn't work with my play style because I want most people to like me, plus I try to do as much as I can before long rests, using up all party members abilities before going to camp. Efficiency, you know? But no. If you want Gale, you camp after one interaction, don't do anything other characters like or their scenes will get precedence, so you feel like you waste 3 or 4 days, which doesn't make any sense when you have a tadpole in your head.
Like someone else said, something needs to be done about this. Maybe make the characters' scenes possible in the same camp time as others. So you could talk to Astarion about the stars, then talk to Gale about the mirror, and Wyll about whatever.
