I just started another Lost Valley run, and frankly the worst perps of popups aren't reactions. They're those actions where every time you hit you can add damage to the hit. Like Smite and cleric of mischief extra damage. That is annoying. However, been through multiple battles so far and not a single reaction popup. It's still early game, mind you, but the point is that it's so far not intrusive even remotely. It's just not occurring.
I do sometimes wonder if we're swatting at gnats and making reactions more complicated than they need to be. An occasional pop-up here and there for a reaction isn't combat flow shattering.
