As a consumer, I host and run Zoom meetings as president of several local ham clubs. I run the club business presentation first, then mute everyone and then let the presenter share their desktop (co-host). I watch and occasionally do some "moderation", but we haven't had any problems.
We had Bob Heil speak recently (he was awesome) and he was switching sound from device to device constantly to do some live demos with absolutely no problem. He also had several video feeds he switches between with no problem.
As a presenter, I've done two presentations for different clubs. They were the Zoom host and there was no problem. I also switched between two different webcams and my desktop during my presentation with no issues.