How should heating consistency between positions be evaluated when buying a rotating clay-pot cooker?

Do not judge consistency from a single burner on a demo unit. First check whether gas pressure holds steady, all pot supports sit at the same height, and every burner is free of carbon buildup or blockage, since these three points drive position-to-position deviation. In a real trial, load identical rice and water into same-size clay pots on every position, fire them together, and compare crust formation time and thickness, noting flame color and size. Testing one position tells you nothing about a multi-position machine, and uneven output usually shows up during continuous service. At handover, run two full-load rounds and keep those readings as your benchmark for future claypot rice batches.