Check the ttl of your transmission again. The Chair should maintain that position, and not take any active part in the technical side. They're there for eliciting questions, for opening and closing the session, and for telling the audience to address their questions to a microphone. The chair can sometimes be the speaker if they know the technology. Drives the wb, vat, camera control.
Monitors control wb.
They should maintain the control wb at all times, reporting problems to the technician. Fixes anything that needs fixing. If necessary, chair and technician can be combined.