I don't see a Bethesda-style slider customization feature. Maybe some more presets (still hopelessly crossing my fingers for the chance we might get some more lore-accurate elven faces to differentiate the elves from the half-elves and humans)
What could plausibly be added, and I'm crossing my fingers for is some hair styles for large-eared races that don't clip through their ears. There's some amazing detailed faces in this game, but the effect is...I don't want to say 'ruined' but rather undermined when their hair and ears clip through each other on four-out-of-five hairstyles for elves, gith etc. Helmets have this problem too.
I'm hoping for some piercings. Barbarians get them, but only in a limited manner. Would be nice to see some more of that for the rest of the classes.