Great questions indeed. I think it is quite relevant especially if you think about the different parts of Public Lab practice, i.e. the distributed research and development (tools and technique development), the on-the-ground site research, and outreach and education. Being mostly engaged in the latter, I would link these questions to the two braod aspects of outreach/engagement: first, how many people does it take to plan and set-up for the event (good to know to avoid stress and facilitator burn-out) and how many people can do this activity to have meaningful interactions (both minimum and maximum numbers). I think these are great questions and PL practitioners can share their tacit knowledge and experiences on these - as I think many of us have asked these but haven't actively documented it.

Great idea, Jeff. This is an especially helpful field for PL activities like balloon mapping and kite mapping - which require multiple people and hands.