However, stat rolling in multiplayer would be a fucking nightmare for everyone.
All problems you mentioned are solvable.
And its not even hard.

First of all, when you play with some people, you (and now i mean whole group) should be able to agree on certain rules for that game ... if you all agree on not rolling stats, then dont roll stats > problem solved.
Yes, anyone can roll stats and just not tell you ... i presume you will notice tho.
Tell me honestly, do you really wish to keep a person who dont give a shit about anything and do whatever he wants?
I wouldnt.
I would kick him out, and wouldnt even feel bad about it. :-/
But to each their own i gues, just dont blame sytem for it.
Second:
Maybe im naive ... but i can imagine it shouldnt be too hard for Larian to give host of Multiplayer option to just not allow this option.
Solved again. ^_^
1) There would be the issue of fairness - in multiplayer you want everyone to start on the same page with the same level of advantages, especially in a game where there is some competition BETWEEN players that is inherent.
Every time someone mentions rolling stats, i mention infinite point buy ...
It have same results, it just saves player time.
Your group agree they wish to feel stronger ... but nobody wants to reroll their stats thousand times?
No problem ... you agree on buffed standard aray ... lets say: 8, 10, 12, 13, 15, 16
(It was first outcome from stat roller on internet)
You "point buy" theese stats as you see fit and problem is solved.
Can someone cheat? Well, of course they can ... but that was solved abowe.
2) No one wants to wait an hour or two while some dingus compulsively rolls for the "perfect" stats.
Again, key to satisfying multiplayer is comunication ...
You should be able to agree on anyhting that feels good to everyone ... if you are not, im affraid what is waiting for you will not be pleasant multiplaer experience.

3) Or worse if you only get one roll, and somebody doesn't like it forcing everyone to start character creation over so they could "get a better roll"
Honestly this whole idea of that restriction feels idiotic and unnecesary to me.
It solves nothing and only makes people angry ...
If that was Larian goal, they should have sell Pacman instead of Baldur's Gate III.
