I haven't either, although recently I've resorted to having him suicide using traps and setting fire to spider walkways to trigger the required death scene earlier in the game. It has also occurred to me that my characters would rather romance Halsin, anyway. A relationship that requires the level of micromanagement that Gale's does hardly seems worth the trouble and certainly loses its "romantic" feel.
Although, the micromanagement may only be necessary if you want him as a party date. It's possible that a more leisurely romance could blossom later in the game if you have sufficient rep with him (which I would actually prefer). Regardless, if he wants to court my characters, he's going to have to be a little more forthcoming and flexible.
You need to trigger his mirror image scene also by resting before doing the intro fight by the grove gates. Then it's a game of doing enough actions per approval tier and camping then. You have to find a way to advance the story without advancing his approval, so you gotta stagger the content that gets you his approval, by doing things like killing goblins at the camp or doing the harpies without gaining approval too quick.
Thanks for the tip, but I've been getting all but the weave scene, so I think that the issue (for me) really is that he's not been dying early enough in the game if I play normally--and that it's hard for me to feel romantically about someone I have to kill off before I can capture their interest. It begins to sound like the basis for one of the books we might find. I'm really not sure why the death sequence needs to happen so early or why achieving exceptional rep couldn't trigger a substitute scene where he explains what you'll need to do if he does die. Perhaps the dev who designed it spied on me monitoring Gatekeeper after each conversation with Anomen to make sure I hadn't "turned off" the romance and thought that a similar experience would make BG3 feel like a real BG game.
And, yes, before anyone expresses shock that anyone would want to romance Anomen, I am the one person who did. It's not that I was keen on the early exchanges, but basically that I can forgive those because later, when my character really needs support, he tells her that he'll follow her into hell and then does so. Knowing you can count on someone can be a real turn on.
