I feel like I would constantly be pausing and confused.
The good RTwP games have tons of triggers for auto-pausing, which is critical so you're not constantly mashing the pause button in combat. I like the TB combat in BG3, but as you said, actual simultaneous action would be very nice.
What I really want to see in BG3 is a real pause feature added to the non-combat real time. Maybe I'm stalking a creature and want to make a number of simultaneous movement/action commands to party members. I'd pause, give each character their marching order, and unpause. Need to get up for some reason? I wish I could actually pause the game. It's not like anything is likely to happen if the party just stands there twiddling their thumbs, but still, it feels off to not have a for-realzies pause feature