Astarion is not lawful at all. He's pretty definitively a chaotic evil character. He loves causing pain, loves it when you kill indiscriminately or start unnecessary fights, and likes to provoke people into violence. All without an actual end-goal beyond his own personal enjoyment. He also complains when you diffuse situations and avoid conflict even if those conflicts would have only hindered your quest to deal with the tadpole.
He has basic manners and the good sense to not piss off his allies, but that is a long way from being lawful. He's just not full meme-tier chaotic.
Well, at least someone sees it same as I do. I thought I was out of my mind.
have some redeemable traits and 'good' deep down, which comes out as you get to know him
Using information about him that we have in early access and first act, I didn't see anything "good" in him, so I'm wondering why you think he has it. But if it's because of date files, then I don't want to know.