Preparing Plasterboards for Microcement

[@user-xf2qt5il7n]

What is the strengths and weaknesses of using plasterboard (not moisture resistant at that) over a tile-backer? How similar is microcement to engineered stone, with the later's silica content being quite a health and safety scare in Australia?

[@adrianadios5041]

Can you plaster the plasterboards and then use microcement? In that case would you seal the plaster first with pva? Or just seal with microcement primer?