Remember, Larian is aiming to make the game more friendly to newer players. Being stun locked by enemies for infinity until your party dies isn't fun. Everyone hates being stun locked (except maybe some of you masochists out there).
Easy fix, make it 2 turns on easiest difficulty, 3 turns in middle one, 5 turns on highest one.
Sounds like a solid suggestion to me
Here's an even better one. Don't give enemy spellcasters disabling spells in the first place? It's just as bad if not worse that they have every cultist cleric or another excuse for a caster Fireballing your party. There are
so many spells to choose from that would fit evil death clerics better. It seems like only Fireball exists for Larian. Vampiric Touch? Bestow Curse? Animate Dead. No. They Fireball you.
All the best CC spells have been balanced with a Concentration requirement in 5e already. And Concentration is much harder to maintain in BG3 where you are constantly bombarded with elemental damage. And the enemies are always scattered over a huge open battle area. That's two significant nerfs to control spells already.
Just give them their actual 5e durations.
BG1 and BG2 are also irrelevant in this discussion, 5e is an entirely different ruleset that has already fixed the save or lose situations.
