This thread was made before but let me reply to you again.
The pop up box is dumb. Why? Because it would pop up EVERY time there could be a reaction. now imagine that with the things you mentioned.
There is of course an easy solution to this, but its a bold one:
Have a button press to open the reaction Box. Basically a timed button press.
The enemy turns to run away? Press a button to open the context menu to do an opportunity attack.
Simple.
That way the gameplay is
A.) Much faster than with a Box that pops up by default
B.) much more controlled than it is with larians implementation
C.) you actually have something to worry about when its not your own turn, something that esepcaily people in multiplayer will certainly apreciate
