Astarion's not a good choice for an ace relationship because he as a character is not ace. Part of his whole deal is reclaiming his body and sexuality for himself.
I agree that it's disappointing that there are no ace options at all though.
He's like the horniest party member (he's constantly flirting with you) aside from Katlach, Lae'Zel and Halsin, personally Gale and Wyll seem more susceptible to being ace due to being more of a slow burn already, sorry but Astartion being ace just seems about out of character as Luke Skywalker being a lonely nephew murdering hermit, personally I would recommend making Halsin ace, since the guy clearly already needs a massive rewrite, from what I've heard so far, or maybe clone Astarion with a DLC companion called Acestarion, I mean being the clone of an already traumatised vampire, just adds an extra layer to angst.
