Sorry if this is a very basic question for some, but when would you use a Belgian yellow coticle stone, I mean at what part of the honing process?

I have 400/800/1200 grit natural Japanese waterstones, a Norton 4K/8K, and a paddle strop with 1.0 and 0.5 micron pastes. Where in this lineup would a yellow coticle go?

Any advice appreciated. I'm wondering if I should pick up a stone while good quality ones are still available.