How to manage large virtual meetings?

IMO every meeting should have an agenda based on questions not topics. EVERY item should be a question that the group is expected to answer or offer insight on. If meetings are just for information, they are a waste of time—just email the information or publish it in a selfie video.

For me, I would ask an important question based on each agenda item and ask everyone to use the Chat feature to send in their answers. Be sure to record the chat sequence so you can calculate/compile the answers you got. You said “large” meetings, so I’m assuming 70+. Or even 40+.

For example, if the first agenda item is “Should we continue spending research funds on the XYZ project?” my question might be, “If XYZ succeeds, how would your business be affected?” or “What do you think the odds of XYZ succeeding are and why?” Do not put out an agenda that says “XYZ Project.” AND you could collect this data with a Qualtrics or Survey Monkey survey that would save people’s time even more. AND you’d have automatic compiling and know who hadn’t responded. So, is your meeting really necessary?  WHAT is the purpose of the meeting?

I’ve become vehemently opposed to topic based agendas—they just end up in endless repetitive discussions.

IF you are having these meetings just so people can see each other and thereby “reconnect” you might break it up into smaller meetings of no more than 15. And be clear on the agenda—or it will devolve. “What’s the best thing you were able to accomplish this past month?” Or “What’s the biggest challenge you are facing this coming month?” Or “What’s the most important thing you learned this past month?”