Those molds are becoming cheaper and cheaper. I suppose it's because they use an EDM electrode to burn the shape into the aluminum. The electrode can be used over and over. They usually have a roughing electrode, and a finishing one. These do-it molds probably use one that's kind of rough, but who cares? Why do you need a pristine surface finish on a jig? You're probably going to powder coat it anyway.
I use the Lee production pot also, and have had pretty good luck with it. It was leaking but I finally watched a video and figured out what the screw head was for.....Duh. Anyway I've never needed flux. I have an old spoon laying around to remove all the floating impurities that build up. Once they are removed, the lead is pretty shiny and beautiful.
Regarding the powder paint, I probably need to get, ( or make) a device that shoots air into the container of powder, like an aquarium pump, to create an air Fluid bath so the coat is nice and thin, and evenly distributed. This also will help prevent the eye from closing, saving you the extra step of cleaning the eye out. I also add the last step which is to bake the jig heads after the initial application of paint. This step is very important and makes the paint tough as heck!