Cisco Webex meetings currently streams to Vbrick Rev the UI that the attendee sees is a VBrick UI such as as the presentation and video of the loudest participant from the Webex meeting.
The layout and Q&A in Vbrick is tied to the Vbrick platform. There is no linkage today between chat and Q&A panels on the Webex side with the Vbrick platform. I would propose you decide on one interface such as the VBrick side so the attendees can ask Q&A there and get responses while watching the video and slides.
I’ll see if Vbrick colleagues want to add anything more on this.