Perhaps when you become a spawn, just before you wake up the game forces you into a limited character creation screen where you can choose the type of fangs and the new skin and eye colour? Everyone should be happy then.
As a side note, I always wondered why Astarion has unique eyes and fangs in comparison to his brethren. Even Cazador has a reddish glow in his eyes.
Also, if Astarion is ascended he should probably get his reflection back, after all he's supposed to benefit from human perks.
For one, I was hoping to gain insight into the real downsides and get a new perspective on what Astarion had to go through in being a spawn. Sure, we're an Ascendant spawn and we certainly aren't created the same way he was (vampire bride theory makes the most sense) but, there's no explanation into what that means. Like, do we not have bloodlust? Where are the moments where we get real urges to rip someone's throat out?
Astarion had centuries to master his cravings, as stated in Cazador's dungeon when explaining why letting a bunch of new spawn out into the world is dangerous. But we're brand new and there aren't any cravings at all? Why aren't we affected? Why isn't there a long rest scene of you trying to suck someone dry and our master, Astarion, having to pull us back and teach us how to control it? Also, seriously missed opportunity for him to throw it back in our face about how upset we may have been that he tried to kill us in the beginning. Could've been hilarious to hear him on his high horse going "Not so easy, is it?"
That would have been such a cool RP option to have in the game!
But indeed it looks like there are no downsides for Tav, I guess Astarion's blood is OP like that. Tav can probably enjoy all the benefits of being a living vampire as he does (as long they stay near him), just doesn't gain new abilities like summoning creatures, and so on.
As much as I enjoy some angst, I'm actually ok with it, because it makes the ritual route more enticing and both can live a happier life. It's clear Astarion doesn't want Tav to suffer like he did as spawn.