Nothing thick about that, ask questions until it's fully understood. Enamel paint (or any other) does not take longer to cure on 3D printed parts than it does on kit plastic. By nature, it's just slow to cure. Thinning with lacquer thinner helps speed up the cure time, regardless of what part you are painting. I think you'll find that most builders using enamel paint will thin with lacquer thinner. It has sort of become the 'go to' thinner for some time now. I am a regular enamel user, and I thin with regular hardware-store lacquer thinner, or Mr Color self levelling thinner (which is recommended for painting bodies, and is suitable for lacquer paint).
It's worth keeping in mind, too, that drying and curing are two different things, though the two terms are frequently used interchangeably. Paint can feel dry, but not be fully cured. Enamel can feel dry in a day or two, but may still take a week or two to fully cure. One trick is to use the sniff test. Smell the painted part close up. If you can still smell the solvents, it's not fully cured. Parts may be handled once they are dried for a while, but I recommend waiting until fully cured before polishing.
A food dehydrator can be used to speed up dry/cure times. However, I haven't used 3D printed parts in a dehydrator, so I can't personally recommend it, but it works great on kit parts. Perhaps someone can chime in with info on using a dehydrator with 3D printed parts. If you are interested in the dehydrator technique for your enamel (or any other) painting, there is a lot of information available on the forum. Here's a link