I would love the Master of Disguise Rogue Background with the ability to change your appearance throughout the game or at least have 1 persona you could change into as a special ability. So, you could create 2 custom character appearances at character creation, one for your main appearance and one for your alternate ego.

My wife played this where she was an wood elf rogue arcane trickster named Diadell who was a master of disguise. Her alternate ego was a human named Anna the Barmaid. Now that was fun.

But, more to the point of the OP, yeah, I miss being able to even just write in my own backstory onto my character. I really wanted to do that with all of them. I know no one else will see it, but it was always fun to have.

I think one of the things that really bugs me about Larian's stance on D&D 5e Tabletop not being able to be translated into a video game format is that when my wife and daughter and I play D&D we use an app on Google Play Store. It guides you through character creation, has every race or just about, every background including custom ones, has every rule built in, a ton of regular items including all starter equipment, helps you with level ups so you don't have to do all the brain work yourself, manages spells, manages HP... I mean, it does it all, and it's really easy to use. It even has the background options like flaws and stuff.

So when I heard BG3 was going to be based on D&D 5e, I thought to myself, "Surely if a simple app can manage characters that well so that I can actually create and manage 6 characters myself with no problem at all, SURELY BG3 with all its budget and such can pretty much take that app and put it into the game and it'd be awesome with graphically rendered characters and settings and enemies using the stats from the app, because all monsters are in the app too, and just put all that data to video game characters. Then tweak the rules a bit, because yes, some things wouldn't really work well in a video game, I get that, and you've got an awesome D&D 5e game.

And by rules that wouldn't work, I mean things like spells that help you detect weather patterns and jazz... you know... things that wouldn't really have any value in a video game. I don't mean rules like height advantage and backstab and all those homebrew things they developed.

So, ahem... sorry... back to the topic... Why the heck not give people the option to add backgrounds and such? I mean, seriously. It doesn't have to be mandatory, just like in the app. You don't want to put in a background, then don't. Just skip that tab and move on. But for those who want a background, why not include a simple background section that players can reference now and then just for fun to see what kind of personality and background concepts they developed in case they've forgotten? Plus, it helps players remember their concept for their character more if they write it down when they create the character.

Anyway... Character creation is simple right now, and I get that for those who don't play D&D, they don't necessarily want a ton of options. They just want quick and easy and move on. But you've got to give the hardcore D&D fans what they love too. Even if I have to click a button to open a separate window or tab or something, at least let me have the option to spend some serious time on my character if I want to.