@Celesti4 I guess we don't know if it's truly scrapped- But rather that there's just no mention of the "looking for immortality part" (shame, because it'd add a layer of depth to that one dialogue where he insults Cazador's servants for seeking vampirism) and that the artbook tends to have some outdated info that makes it seem it was made earlier in development. I agree that the game still does heavily, heavily, HEAVILY imply he was a very corrupt magistrate, and find it strange there's no follow-up on the tidbits he drops about how his death happened in act 1 that were clearly written with a follow-up in mind. IIRC, one of the datamines I saw in Early Access had him allying by default with this monster hunter guy called "Spencer" against his spawn siblings (you met them in act 2 here). That might have tied into it? I can't recall if he was a Gur, might not have been specified. If so, it could've been part of his arc.
And about Idle Champions: my bad. His age there was never 239, I'm just tired and didn't get it right. They changed it to 263 indeed, and that age is a band-aid to try to fix the tombstone inconsistencies, except it doesn't deal with all of them. IIRC (might be wrong, I'm so sleepy!) what they did to get that age was add a 1 in front of both the year he was born and the year he died, and changed the current year to 1492, which is the correct date but not the one he writes down on his tombstone ingame, he puts a date that's like 25 years before the events of the game but acts like it's the current year. Thus the fix 263 is born.
Astarion's only mention of his elven heritage ingame are him talking about his pointy ears, the vague sense of high-elf superiority syndrome trope, and that one Durge conversation where he mentions Evereska, if that's even considered addressing his elvishness. They really do treat him as a human, in a way they don't do for the other elf companions. It's a bit jarring when the story treats him as extraordinarily ancient at times, because there are 2 characters older than him that you can recruit. I guess immortal vampires and how they clash with mortals' lifespans doesn't gel well with worlds where people can naturally live 750 years. (Don't take my nitpickiness as me hating on the game, these are all extremely minor and trivial complaints and I do love BG3)
EDIT: Re: Spencer the monster hunter, I wanted to say I looked for my source because it was an interesting thing but the tumblr who datamined all that recently deactivated. That's such a shame because they datamined a lot of stuff that most people don't know about. The only other mention I've found online of that guy's existence is this VK post, although there's some issues with what seems to be the automatic translation?
https://m.vk.com/wall-178381386_183365?lang=en.I'm skimming over, but it's missing other parts of that datamine about how a bunch of Astarion's siblings were (at Moonrise Towers?) playing cards or something and then saw him and cheerfully asked him to join them at the table or something, to which he got mad and started bragging about how he's now free and doesn't have to do a damn thing, something like that. And Spencer comes in, and he prefers to side with him. In this version of the story, act 3 datamines had the spawn seemingly be happy about Cazador's treatment of them, saying he was a strict boss but that he still fed them well. Could've been them being compelled to say so, I guess, but also could imply that Astarion was extremely punished in comparison, which was something heavily implied in EA (that he was "Cazador's personal slave, never to leave his side unless instructed to") and taken out when they changed how Daisy/The Emperor works. Honestly, back in EA everyone seemed to conceive Astarion and Cazador's relationship not like that of an abusive father and his son, but of like, an extremely abusive """romantic""" relationship.
