This is mostly what it would look like with popup until someone answer "Yes/No" in BG3. (ok, the animation would probably be a bit slower and wouldnt look exactly the same, except eventually if someone is on a ladder)
IIRC this is what happens in Solasta in multiplayer. When another player is eligible to use a reaction, all the animations sort of lock in place and the message at the bottom of the screen changes from 'ENEMY TURN' to '[Player] IS CONSIDERING A REACTION' until the eligible player chooses what to do.
I did a full multiplayer playthrough of the Lost Valley campaign with my tabletop friends. It was loads of fun, even if the writing towards the end of the campaign kinda drove off a cliff, but I guess that's the trouble of designing a campaign with multiple possible endings.