I understand new plaster should have a diluted coat of non vinyl mat followed by top coats of the same but how many months need go by before vinyl paint can be used?
Exciting walls that are dry may need a thin skim to make a nice surface to paint. They dry completely in 3 days and can be painted with whatever paint you want. New block walls that are plastered can have moisture in them that can take 6 months to dry out totally.
Oh. You would use a new plaster emulsion or contract emulsion that allows the surface to breath and dry out, on surfaces that have moisture in them. Vinyl emulsion is fine on a dry walls that has had a thin skim. Vinyl emulsion can trap moisture and cause problems if using over damp surfaces. I hate the contract/new plaster emulsions though. Terrible finish
The paint manufacturers don't differentiate between skimmed walls and base coat/skimmed walls, new block walls etc. Perhaps a lot of time has been wasted by using only contract matt following up later with vinyl colour.