I prefer vinyl over powder paint as well.

But when using powder paint, I like to heat the jigs to 250 degrees for 5 minutes in an older toaster oven designated for the job, to get a consistent jig head temperature, before adding the powder paint. Heating the jig to 250 degrees for 5 minutes, you'll get a light non melted powder paint coat. Be careful to not knock the non melted powder painted jig head around at this point though before baking, the powder paint comes off fairly easy at this point. Too hot of a jig head before adding the powder paint, you get way more melted powder paint on the jig head than is needed. Mount the jigs upright in a foil base before baking. The excess paint when baking will run down the hook shank, keeping the jig heads round shape.