I'm not sure if it is still universal, but this was once frowned on for use in PBEM.
It's one thing to play a game versus an opponent with a lower win-loss/ELO, in a scenario where the game reflects a balance that favors one side, over setting the advantage bar feature in a more balanced scenario.
Ladder games usually should be played on an even playing field. Even if that field is a scenario that seems unbalanced to one side?
I guess two opponents can agree to it before they start play. Though, I would never use it. And, I think that someone who would change the advantage bar during play would be using a stunt method to win?
If it's not going to be reported on the ladder, it makes no difference to me.
I guess others can weigh in on this.
HSL