I currently have 3/4" plywood as the subfloor. Do you think that 1/4" luan would provide enough impact and puncture resistance to protect the XPS? The goal here is weight reduction, with an added benefit of increasing the R value of the flooring.
Thinking about it I would probably provide a frame for the heavier components in the van like the fridge, however the majority of the flooring would be this laminate.