I don't think its elegant, but you have near total control - and I'm prepared to pay that price. I have just finished another run through of Solasta, so speaking from recent experience too. I don't want assumptions made on my behalf by some gaming system. That sacrifices my agency. Sure, some people won't want that. Give them the ability to set up some sort of defaults. I want *full* control.
Same here. I wrote recently about how reaction in the way Larian implemented turned out to be one of the worst aspects of playing Patch 7 (especially in Grymforge):
The final boss in particular (that I have to admit I liked in principle, despise not being exactly the most standard "D&D-like experience" out there) highlights how terrible the current reaction system can be, not to mention it makes the absence of ready actions more annoying than ever. Before finally dispatching said boss for good I experienced several cases where an autoattack/reaction triggered when I was trying to lure the golem in a specific direction, usually with consequent outcomes that forced me to a reload.
It's also worth noting that one downside of "new shiny UI" introduced in Patch 7 is that it makes circling between ALL your characters, selecting the "Passive" submenu and disabling their Attacks of Opportunity even more cumbersome than before. And it's not even a "one and done" thing, since there are moments during the same battle where you DO want to take these juicy AoO, while in others you definitely don't, so it's a constant "cycling and switching toggles" that becomes annoying fairly quickly and makes me chuckle a bit when I think about the people (a minority, admittedly) that in the past months said "they would hate a Solasta-like reaction system with quick case-by-case confirmations because it would slow down the combat".
If the issue is just "making it look fancy because a rectangular pop-up is lame" then THAT is the issue Larian should address, but removing control from reactions is NOT the way to go.
The issue for me is more that Solasta's window is constantly popping up. Sorcerer spell cast, popup asking if I want to use metamagic. Barbarian, asks if I want to frenzy. Paladin, asks if I want to smite and at what level.
I do like what Fuji said. Maybe some sort of toggle so if I don't want the game to ask me if I want to use metamagic, I can toggle it off until I want to use it again or something.