Do you have data showing the bonding characteristics:
250F @ 'X" time
300F @ "y" time
What is the PMT (part metal temperature) required to cure the coating? For example: if the PMT required is 200F, the time to get the part to temperature will be faster if the oven temp is set at 300F rather than 250F.
You can clearly see the relationship if you have a thermocouple monitoring the air temp and a thermocouple bonded to a steel substrate. You can clearly see the air and part temp profiles. You can look at the ramp up time, and also check the integrity of the electric heaters by comparing profiles over time.
https://www.flukeprocessinstruments.com/en-us/products/thermal-profiling-systems/datapaq-oven-tracker-systems