I'll also add that High Ground's +2 bonus only applies attack rolls, further widening the difference between attack-roll and ST spells. I don't think that all spells should get a +2 to their DC while on high ground (why would being on the low ground make it harder for enemies to make their e.g., Con or Wis STs), but it's something additional to consider.
That said, is there a universal AC lowering for enemies in BG3? Goblins are the main offender as I recall, having both higher HP and lower ACs, but other monsters/enemies?
