Honestly, the powerful character starting at level 1 never really bothers me - it's just a convention of the genre. Take POE2 for instance - you finish POE1 as like a 15th level badass or whatever, only to wake up on a ship back at level 1. It's just how it works. For me, arguing that for reasons, the character shouldn't start the game at level 1 is like complaining the character doesn't have to stop to take a leak behind a tree every few hours.
I am quite the opposite - power gain in PoEs always rang very false to me. Convention of the genre is a right way to put it, but it doesn't necessarily make it inappropriate. How gameplay loop and our identity in BG1&2 is tied is one of the reason I would put it higher than many other titles. There is cohesion in there, that others RPGs lack. In case of PoE2 reset to level1 is just another thing that make me wish that Deadfire had a new protagonist.
Now, I would be interested in seeing RPG, that would focus more on horizontal, rather than vertical progression, but it is not really possible for D&D based title. Still, if you are stuck with mechanics, I think you should write around them, not write story and characters unappropriate to the mechanics.
