Currently in EA sound cues are too few and far between, so I'd suggest to add a wide variety of cues to the mix, as they are not only adding atmosphere and dynamism to the process but also providing additional feedback on what's going on on the battlefield and... emotions! Sound cues from companions in BG2 (especially in battle) are one of the most memorable things from the game for me. And since BG3 has turn based battles, importance of sound/voice cues from companions (and enemies!) is huge!
Voice cues & banter during battles those DO NOT have to happen on every occasion, but rather from time to time, depending on the severity of situations, randomness, and maybe some other factors:
on critical hit/miss
on opponent's (attacker) critical hit/miss
on critical hit/miss of other companion nearby
on being poisoned/confused/chilled/etc or otherwise affected negatively
on low/critical health
on low/critical health of other companion nearby
new enemy appear in visual vicinity
performing sneak attack or other specialized attack
on opponent's death (after successful attack)
on other companion's death
To imagine how fun it might be, you can find a suitable Minsk quote for almost all of the above Or try PoE Deadfire in turn-based mode.
(more) non-combat voice cues & banter also something to consider, as for now I don't feel that characters in party have enough interactions with each other, while not in camp. Some ideas on when they can occur: