In the UK this was known as ARTEX a cheap solution to avoid plastering being applied strait onto plaster board, and in the 80s it did contain asbestos.
I have plastered over this in the past but it needs the correct technique.
Scrape of the worst of the rough nips (messy) and apply a thinned coat of PVA, when dry apply a second thicker coat and start plastering when it is still tacky.
I have never had a failure following the ones I have done. ( I did have a decorating business at the time).