In point of fact: Larian is *not* getting around to some kind of pop-ups or really be creative to create an unobstrusive system, if they want to implement reactions and other abilities like sneak attack somewhat faithfully.
And in my opinon they really need to to that. Paladins and Rogues would really get the short end of the stick if they just stick with the systems in a similar way as they are now. Sneak attack is a mess atm.
Not to beat a dead horse too much, but: Look. At. Solasta.
Its a flawed game in many ways. But by avernus, they have the 5e system down. If they want they can have a simplyfy option with toggles, I dont care. But if there is no faithful implementation of reactions there is a full and very important part of the action economy that is missing. And it would impact the quality immensely.