The least amount of heat to gain some adherence is gonna be best. A second pass if the painted head looks powdery.
I strongly suggest you read about curing. The application can be sloppy but you want the curing to be done correctly. Time and temperature can be regulated then. There are recommendations for time and temperature for a very good reason.
A chemical change occurs. Crosslinking for strength. However, finish and color are what you will be most interested in. Thermometer in a small oven is gonna be far more important than this heat source. Just get the paint on board….then cute it.
Check out Jungle Jim’s stuff. Look at DrNips stuff. Look at Grumpy and the others who have done this stuff long before either of us. Fluid bed is a distraction. Swap out containers right away, getting wide mouth and shallow containers. Keep powders inside the A/C untilneeded.
Maybe they will bite this one……