I've been playing Solaste a bit and now I know why Larian decided to implement automatic reactions.
The popups are terribly annoying and seem disconnected from the game.
I'm afraid something like this would be even worse in multiplayer.
On the other side automatic reactions are just plain stupid. In a sense that they cannot think. A reaction is something where you can *decide* something while it is not your turn. And in the current implementation you can't. Some class features like smiting and sneak attack are similar atm. The paladin will feel outright disappointing, as they are pretty much a nova class that excels on doing insane amounts of damage in crits. But with smiting out of you control you just do a little more damage sometimes. But I'd argue that the best strategy will be to not waste spell slots on smiting. They are rare and you have other buffs. But then again: why play paladin? LoH? Its okay but in a game where any stale bread does the job who cares? Probably you are better off playing a heavy armored cleric. Better spell slots, better and earlier spell list.