This sounds great but my concern would be structural long term and/or warranty. Can you comment on either?
The FGM are built with metal fibers in the refractory concrete. Such fibers act like re-bars in a concrete slab and prevent cracking.
The 3 years limited warranty for the FGM applies on the WFO mounted on trailers as well.
Often for food trucks, the oven will outlast the vehicle it is mounted in. The owner ends-up moving the oven into a new truck, just to stay how durable the ovens are.
Let me know if you need further details.