I've been playing The Quarry on PS5 which is basically a game of quick time events and it got me thinking about reactions. I think others have suggested this before, but what if reactions played out more like a QTE? Zoom in on the character as the attack comes hurdling towards them in slow motion. Then all available reaction options show up on screen to choose from with a clock/timer winding down. It would make reactions a little flashier than a simple popup and maybe add a little gamification of trying to decide what to do before the timer runs out. I don't know if that would get annoying if it happened constantly but... just a thought.
This has been suggested as the aesthetic in a few other threads that talk about it - basically, to smooth the feeling of actions stopping and starting, the action slides into an exponential slow-down while the player chooses, slowing more, until it reaches a full stopping point if the player still hasn't chosen by then - but if they choose quickly, there's no stop at all, and just a brief deceleration of events - even active time combat video games do this within their combat engine, with tactical slowdowns for dodge frames and critical opportunities. In a game like BG3 this would be primarily an aesthetic smoothing quality of life detail, for a proper reaction system that does ask the player each time... again, with options for a time out pass-over if that's what the player wants (and which would probably be a necessity in multiplayer, I'll happily admit).