I am in.
We have been using Slack and Google Hangout at work, before coronavirus. I also used Skype, Zoom for meetings with various clients.
I forgot if it’s possible to do instant messaging on Zoom, but on Slack you can, and unlike Hangout, the messages are persistent, which means the chat history will be stored after the call is ended. On Slack we can create a general channel to house the large group discussion, then people can create smaller channels based on topics and start video chats there, to mimic breaking off into smaller groups. Not sure if it’s possible to do the same on Zoom or other platforms.