Yeah, this.The problem isn't so much over scaling or scaling up with the player, the main problem is the trravel to skell is suggested at 16, yet the missions when you get there are a lot lower.
The actual levels are completely out of whack :/
The quest for getting to Skellige is set at level 16, but then the main quests go down to lvl 13-14 again for no reason. Other than having had some disappointing boss / rare bosses being a bit to easy even on death march (up some of the rare monsters HP or dmg could be a simple solution), I love that content isn't scaled. However having the content being levelled unevenly is a problem.