It makes sense that we don't find anything that belongs to Astarion in the palace. The spawn don't have anything and he's not someone who would keep a journal. I'm pretty sure the clothes he wears are all he owns.
I didn't think he'd have much, but I was at least expecting there to be some sewing tools since he knows how to do embroidery and how to maintain his clothes. He also experimented with making perfumes.
Yeah the real reason is probably "Larian forgot/couldn't be bothered", but we can also justify it as Astarion not bringing things home.
Speaking of embroidery, I kinda miss the “Lamentable is the autumn picker content with plums.”
