Most of the bad mechanical stuff is follow ons from changes they've made from the ruleset, again like a bad DM would, just a cascade of patches to their homebrew system that breaks the system they had that already worked
-Larian puts in goblin encounter -Larian implements their height advantage/disadvantage system (giving a 3:1 advantage for the high creature) -Goblins are now impossible to hit (the basic goblin in D&D has high AC and low hitpoints) -Goblins have their AC reduced to 7 so players can hit them when they are elevated, because combat was too unfun missing over and over -Larian introduces surface effects to everything -Firebolt now kills goblins even if it misses them -Triple the goblin HP -Concentration spells are vastly nerfed by the fire surfaces created by enemies, you have a small chance of holding concentration if put in a fire field - YOU ARE HERE -
this is just going to keep spiraling into more and more dev effort to patch problems of their own making