From what I’ve read the enemy damage/health scaling is gonna be its own thing so I would go into Erdtree with your strongest build possible with the most items/resources. Everything is gonna whoop your ass regardless until you collect the shadow seed things to get your damage up
the thing is, the damage calc in this game takes %s very seriously - Golden Vow and other such buffs most especially. So the Scadutree fragments being straight damage+ and damage- bonuses is likely to be some interesting changes. That said, I believe someone said they were getting like, 3-4% differences from a fragment, damage-wise.
That shyt is going to add up heavy if that's the case. 4-5 fragments giving you effectively permaVow in the new areas, and them being balanced around that...
My first 5 hours just gon be scavenger hunting and running for my life before a spin back with some buffs to settle scores, by the looks of it