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.
It's most definitely terrible half-assed design, and should change before the game releases.
I've done 4 complete playthroughs and only on the 4th after reading the forum threads here did I get enough tips to manage to trigger the scene through very calculated play, it sucks.
Especially because unless Daddy Halsin becomes available, Gale is the only sorta normal charming male romance interest. Wyll is such a weirdo with the self referral in third person to the Blade, he's too full of it for me to like. Doesn't help he talks about his devil mistress even during your sex scene and you need to roll a dice to even get a sex scene.