My experiences with Iron Man modes are pretty good if they are used in games without high luck dependency. In DOS2 it was actually implemented very well because outcomes in that game (especially battles) were more dependent on your tactic than plain luck. In BG3 it seems mostly two different things determine the difficulty of a battle: Your starting position and luck. Especially at the beginning of the game when you don't have many skills. So do you really want to play a hard Iron Man mode on your first playthrough without knowing which battles are waiting for you with a hard save game wipe if your entire party dies? I wouldn't recommend it for a DnD video game. Because there is no Dungeon Master who saves you if you screw up. It's just a merciless machine. I was searching for a solution to make me live with my decisions but without having to throw away my entire playthrough if I get into a situation (e.g. battle) I cannot handle. Skill checks are meant as barrier. What sense does a barrier make if you can overcome it by save scumming? In other games you have hard thresholds you must overcome for skill checks. In real DnD you cannot save therefore no savescumming. In a DnD video game you have to make adaptions to still follow DnD rules but also consider the different environment (possiblity to save). I simply provided a possible solution that could be an option in a settings menu. Of course who absolutely wants to save scum could deactivate it.
