I hope the game adds this as an option. I would love to have a consistent challenge regardless of my character level across all zones and chapters. Also, I'd love to replay it in a New Game + style where I keep my level and powers and can move through the game with them.

I have done this with Pillars of Eternity 2 mod and it is fantastic fun. I don't miss actually leveling up at all, and it presents new and interesting ways to approach all the battles, even some of the earlier ones. Great stuff. At any rate, once the game is Moddable I'm sure level scaling would be one of the first mods created if it isn't included at launch. Which is a good tip that it should be hehe

https://www.nexusmods.com/divinityoriginalsin2definitiveedition/mods/132