Shameless plug, I've been working on solving exactly this problem with Mixaba! Everyone automatically breaks into small groups of 2-4 every few minutes.
Tell me more about Mixaba. I've had the same idea. Rather than brain storming in a large group, break into smaller groups and then mix up the groups periodically. My guess is this would lead to faster group consensus and result in fewer people feeling left out or that they hadn't been heard.
I did a Show HN last year but a lot has evolved since then :) By breaking people out into small groups you increase opportunities for vulnerability and trust-building, and you decrease the likelihood that a single person will dominate the conversation.
It was borne from negative experiences at a couple all-virtual happy hours at the start of the stay at home orders in the US last year.
With Mixaba, everyone joins a single event and regardless of whether you have 8 people or 800 in the event, it automatically breaks people out into new small groups, shuffling up conversations and making new connections between folks as the event goes on.
Shameless plug, I've been working on solving exactly this problem with Mixaba! Everyone automatically breaks into small groups of 2-4 every few minutes.