Unless someone is splashing gasoline around, fire will spread very slowly in an open-topped plywood maze. And heat/fumes/smoke will head skyward, not accumulat

Unless someone is splashing gasoline around, fire will spread very slowly in an open-topped plywood maze. And heat/fumes/smoke will head skyward, not accumulate as they would for an indoor fire. As an organizer, I'd be much more concerned about medical emergencies and inter-personal crime in the maze.