The only way I would tolerate reactions in BG3 would be if they where automated similar to dragon age origins. In that game you could tell your companions to use X or Y when Z needed to be. In practice how would this work in BG3. [...]
Tactics that work like this are very easy to code, and larian has 0 excuses for not adding them in such a manner. If dragon age origins could do this 10 years ago. They can do so as well.
I thought this would be great for BG3 too, but then I realized that tactics fit so well in DAO because it is RtwP and the companions you're not currently controlling are always acting and being acted upon. Thus, they *need* tactics in order to not do completely idiotic things. Giving them tactics allows you to worry less about and do less micromanaging of the others, enabling you to have more fun actually playing the game.
BG3 combat, however, is TB where you're given specific time to control characters one-by-one. You're expected to dictate every one of their actions; making decisions for every character *is* the gameplay. So adding Tactics for reactions only wouldn't fit with the TB nature of BG3, and it'd be a loss of this control.
I think that there is some utility for automatic reactions, but specifically as a setting which determines when you receive Solasta-like prompts.
This would be fine with me! It's a more complicated solution, and probably should *also* include an the "automatic use/promptless" option, but yeah. Set Uncanny Dodge to not prompt me if the incoming damage is under 5; set Counterspell to never prompt me if the enemy is casting a cantrip; etc. Similar to @GM4Him's suggestions but the end result is still prompts, not auto-use.