But for games like BG:3, with a linear main story progressing in acts, it would add to the experience, to have minor consequences for delaying certain things.
The story's urgency is derived completely from the tadpole. By the end of Act 1 you know both that it is not an urgent thing to deal with (the ceremorphosis is in stasis) and that it is more urgent than ever to deal with (that stasis could be removed at any time, causing a violent and instant version of ceremorphosis). So you now no longer have a poison in your head, but a remote explosive. How is that going to carry over to Act 2 and beyond?
Like Pathfinder:Kingmaker did it is fine for me, meaning you have different plot elements that define soft or hard deadlines, like an invasion happens after 20 days of free exploration, or you have two concurrent urgent quests, and there are story consequences for doing one first. The deadlines are always limited in scope and consequences. In BG:3, there should not be one that is longer than one act. So the tadpole thing would be relevant for act 1 only.
I have no idea if Larian knows how much exp they are dishing out in EA right now. Becoming level 5 or even level 6 in Act 1 would upset the balance so much that encounters become trivial. Limiting or removing exp gain at level 4 is a bad way to compensate for this as it discourages exploration of side content.
I really like to do side content and then crush the main story line while being over levelled. There are difficulty sliders to compensate for this. Nevertheless the balancing right now does not work, I agree. The Underdark beginning should be scaled up a level, I think, and the later encounters by two. XP could then be downscaled to ensure that you only get to level 5. Or something like that.
