I am not familiar with the pen&paper version, but as far as BG3 balance on tactician goes:

- Haste in all its forms is waay too strong
- Multi-hit attacks/spells triggering EVERY damage bonus on EVERY hit is ridiculoussssss.
- Feat balance is very uneven, Tavern Brawler deserves a special mention as broken.
- Maximizing damage output on every party member feels like by far the best approach.
- Seems arbitrary which spells are penalized with "Concentration" and which are not.
- Inactive camp members able to buff up the active party is hilariously bad design & further incentivizes using only damage dealers in active party.
- "attack roll" type of attack/spell feels far superior than "DC" attack/spell due to the numerous cheap/free bonuses available to improve "attack roll" chances.
- for the first 5 or so levels most full-caster classes feel like they need to Long Rest too often for spell slots.
- Some Subclasses are total traps, hideously under-performing compared to other subclass choices (wizard, cleric etc...)
- combination of ritual spells Feather Fall, Enhanced Leap and Longstrider completely trivializes all concepts of distance & terrain obstacles, especially when casted by an inactive camp member.