So Ivan from optimum says be careful when layering. Wax will take off wax, sealer takes off sealer. Wax can go over sealer…..sometimes.

jescar power lock can layer on itself after 3 hours. Collinite can on top after 3 hours.

collinite can be topped with itself after 12 hours.

meguiars 21 cannot be topped with anything, even itself.

are there any chemists here that can tell me what determines if a sealant or wax can be topped?

I know you can use beadmaker/meguiars spray wax as a topper for anything. I use these products after a wash as a drying aid and “booster”.