I wouldn’t assume anything Sideshow is doing paint wise correlates to what hot toys does. The videos Sideshow puts out are painting for masters they send to a factory. The factory uses industrial paints with different formulas. What sideshow does also has no correlation to what Hot Toys does.
The weathering is done with some sort of printing technique. It’s not hand applied. I’ve compared copies of the same S1 beskar helmet and the weathering pattern was identical. I do think it’s done after the armor is cleared though.
My first test is going to be to use a cape cod cloth to polish it. If you aren’t familiar with them they’re a gentle polishing cloth that can remove fine scratches from glass without causing hazing. If my theory on their paint application is correct you should be able to polish off the weathering before removing enough clear to make a difference. If so it is much less risky than using solvents like alcohol that can leach through layers and cause hazing.
After seeing some in hand shots and videos of the figure, I think it does depend on the lighting. My other hobbies include painting miniature figures, so my take is that it’s supposed to serve as a combination of weathering and shading to help make it look more three dimensional. Flat surfaces can end up looking very bland or toy like (especially metallics) and miniature painters have different techniques to add depth. This could be shading with a darker colour using an airbrush or successive layers of washing applied by hand. A chrome finish runs the risk of looking very toy like if nothing else is done, the way some toy cars might look.
