Clear coating resin 3D prints
I'd go for the easy option of using a composite setup: Acrylic lacquers themselves are very low reactive and can serve as a foundation before the UV clear coating is applied. The acrylic lacquer itself doesn't change coloration if exposed to sunlight, but the light can still pass and discolor the lithophane.
Your Krylon clearcoat technically is an acrylic paint, but to be used from a rattlecan, other chemicals are added - a whole lot as the MSDS tells us. The list of chemicals besides the paint in that can are Acetone, n-Butyl Acetate, Propane, Butane, Xylene, Ethyl 3-Ethoxypropionate, Cyclohexane, Ethylbenzene,
Bis(pentamethyl-4-piperidyl)sebacate. Three simple chemicals I put in italics - they are very good solvents that easily react with the resin print. Propane and Butane create the pressure in the rattle can, the other four chemicals make up the actual lacquer. I have observed the mix of Acetone, Cyclohexane, and Ethylbentene (with possibly others) softening PLA, so it is totally possible that they react unfavorably with your resin print. As a result, I suggest using a brush or roller to apply acrylic paint from a can (not spraycan!)