Some diagnostics: Check fire, fuel and air.
I carry an extra spark plug in my tool box so I can check for fire when tractor fails to start. My super C started running rough and then quit. It wouldn't restart. No fire and coil was too hot to touch. I swapped coil out and problem resolved.
Another time it developed and intermittent starting issue whether it was hot or cold. That ended up being the condenser.
Check for fuel flow by unscrewing the drain plug on the carb. Probably not an issue in your case.
Check the air cleaner. Back in the day, when I had no building to park a tractor in, rain would collect in the air cleaner oil bath cup and cause a flooding problem. It would start fine but after it warmed up it would run rich and not want to restart easily when warm.