Wow, all day? That's a lot!
My team and others have been having "office hours" meetings where everyone is just working, but often the cameras are off, mics are muted most of the time, and we only do it for a few hours a week.
I definitely agree that there is a lot of value in being able to jump in and ask questions in the moment. That's a big benefit of having these calls for us.
Maybe we should try having them more often. :)