I've run four sessions of a Torchbearer game. I'm getting the hang of it. But when I was talking about it to someone at lunch, they presented the idea of making it GM-less and I've been thinking about that. If my goal is to keep as much of the essential Torchbearer experience intact while shifting away from the one GM model, what changes would be wise and minimal?
There's nothing stopping you from rotating GMs between dungeons. This is what I would recommend.
The GM role in Torchbearer explicitly involves information hidden from the players: the map of the dungeon, potential interactions in rooms, whether a given test will result in a condition or twist, the hidden qualities of previously unencountered monsters, and the backstory of what happened and what is currently happening in the dungeon. Playing Torchbearer is the players exploring the dungeon. Distributing these GM tasks among the players pushes strongly against the Czege Principle—when a person is the author of both adversity and its resolution, play isn't fun.