I recently beat the game on Honor Mode for the 4th time, but with the level 13-20 mod, but I also ran the D&D PHB 2024 (now D&D 5.5E mod), and the mod that increases the number of enemies in encounters, and the random new encounters in the wild, along with the AIO equipment randomizer mod. (Along with a few appearance mods for your TAV).
I was level 18 as a party by end game, I didnt run the increased XP. The final fight was still hard, and the fight with Rapheal was a real challenge even at 17 at that time.