Part of Solasta combat being better isn't just Reactions, but balance.

Anyway, the current system might be manageable if you could interact with your character when it isn't your turn. Like, you had your UI turned into only the available Reactions you had on your hotbar and could use one every round.

That's the most feasible and realistic of Larian's limitations.

Within the framework of the game, there would be no focus on shortening combat with Swarm AI and Swen saying they were averse to pop-ups, only to do the opposite.

Though I still maintain that part of that was an excuse to cover up the poor foresight of their engine and its constraints on a proper 5e system and not what we were delivered.

Regardless, they did not just include Swarm AI for its effects to be negated by everyone having to do pop-ups.