I would be interested in 4x5 format.

My suggestion would be to have groupings of about 5-10 people and have one person volunteer to generate 5-10 identical negative to send to each participant. Each participant would be responsible for sending one 8x10 - 11x14 print of the negative to each of the other 4-9 participants along with notes about the printing process and techniques so that it is a learning experience.

Although a bit onerous, it would perhaps weed out the casual volunteers who take forever to do anything. Some of the blind print exchanges are exercises in patience. People seem to volunteer and then take months to generate a single print so the experience is more exasperating than anything.

Just my take.