Somehow, this scene hits a lot harder when you're not romancing Gale. The way you get to know how much he's grown to care for this rag-tag group of companions and how badly he doesn't want to lose everyone. Something about this not just being about Tav, but about everyone and how important they've become to him is heartbreaking.
I've never been able to develop my Tav's relationship with Astarion in any of my playthroughs other than the Durge one I'm doing now and I find this version of him so interesting. This scene, where Lae'zel uses the Zaith'isk, is so amazing to me. He is genuinely concerned for her while she's in the machine.
I'm used to him expressing his concern in a more snarky, passive way as if he doesn't actually care even though we know he kinda does. But in this scene, he was actively WORRIED about what was going to happen to Lae'zel. Asking if we're just going to stand and watch, helping her stand up after the machine blows up, and just constantly keeping an eye on her. I just thought it was really endearing.
Karlach's story broke my whole heart. There was no good end for her. Let her die, even though she wanted so badly to live. Ask her to live, but she has to go back to a place where she would never be able to live in peace.