You don't have any advantage in Solasta when you're higher. You both know the rules better than I but if I remember well it's not written that you should have any bonuses if you're higher.
Solasta doesn't have high ground bonuses but it does have cover bonuses which seems easier to calculate with its grid system.
Agreed that changing high ground to +2 in BG3 was an excellent decision. +1 or +2 seem absolutely perfect for a high ground bonus (cough cough Pathfinder gives a +1 high ground bonus), and importantly that bonus stacks with - and therefore doesn't invalidate - other sources of Advantage.
Both, I think, are very good approaches. Solasta's map aren't as focused on verticality, so giving someone bonus because he is standing one square above an enemy makes little sense - on the other side grid allows for good implementation for cover bonuses. BG3 high ground has been working very well since they nerfed it to +2. I wish they wwill reign in the remaining homebrew so it adds tactically enhances the game, without overpowering it.
