The problem I have with the Solasta is that it's more of a D&D combat simulator than an RPG. The game itself is quite average and most likely if not for BG3, hardly anyone would have heard about it. I understand that the game is low-budget, so it's hard to expect amazing graphics, but it's hard to explain the story or probably the ugliest interface I've ever seen in an RPG game. If I saw this game somewhere by accident, I would think it is some kind of mobile game. I dislike the chessboard so much but I admit the combat system is OK, but whether it is really better than in BG3 is a matter of opinion. Summarizing, Solasta is a better D&D simulator but BG3 is definitely a better game.
I'm not sure what to think about the reaction system. On the one hand, it's functional, the problem is that I completely don't like pop-ups during combat. There are too many of them. I just don't like them. It would be much better if instead of a pop-up in the center of the screen, for example, an icon at the bottom of the screen.
Regarding the reactions in BG3, I'm not sure if the Solasty system is a good idea. The game is primarily developed as a multiplayer game. BG3 also puts a lot of emphasis on role playing. At the moment, introducing the reaction like in Solascie will significantly extend the fights (many people are already complaining about it), unless we are talking about mindless clicking as soon as a pop-up appears on the screen. The problem will be especially noticeable during big fights like the goblin camp.
I have one more problem with popups which is much more significant (at least for me). Pop-ups take the player out of the game (not sure if that's the right term). Some people would say that barrels or food in combat do the same, but I can't agree with that. In the case of barrels, you have to try to use them in any sensible way, especially since the opponents do not use them too much. Moving barrels is really no different than keeping 30 swords in your pocket. I don't know, maybe I've played too many games before because it doesn't bother me at all. Equipment always treated as something "attached" to the game which doesn't have much sense. Many of my favorite games didnt even try to pretend realism and gave the player unlimited equipment. Eating in combat although stupid isn't uncommon in games. It is also not as big of a problem as some say. Food heals too little and often weighs too much to be useful anywhere but the beginning of the game. Once you can buy better healing potions, it will become useless.