Here’s my try. I used particles to make the textures for the material:
(Colorramp stops: alpha = 0.5, alpha = 0.04)
(ignore the microroughness node, just trying it out.)
Particles were little discs with a small randomized rotation on a plane, and rendered with an ortho camera (the 2x2 duplication of the plane in the image below is just a trick to make the texture seamless, it’s only really useful for painting textures so you can skip it).
The two textures are a mask (composite render with emitter visibility off and render/film/transparent checked) where full alpha/white is glitter; and a normal map (normal pass, emitter visibility on). Images saved with “save as render” unchecked.
All this of course done on the assumption that textures are faster than actually having particles in scene - one I’ve not really verified but which seems plausible. Also that you’re not doing really close up shots, in which case you’ll want particles anyway.