Unless it's hardcore full-frontal from start to finish it won't accurately capture the spirit of the game. They've only got an hour per episode to pack with weird horniness.
ideally it won't even be horny at all - all the characters are entirely naked because they've taken off their camp clothes & then switched to camp outfits in the overworld as a joke, nobody as much as mentions this in the show
That's just it: it's read about, spoken about. That sort of than can happen and I can accept that as a story element that adds tragedy and pain to a character. That's fine, even good. What I saw of Astarion's story as visually presented on screen didn't seem particularly gratuitous (except when Raphael showed up at one point) or at the character's expense.