Looking for help. I have about 8 holes like the images and had various
recommendations. This is what looks like plaster or browning straight onto
breezeblocks. No plasterboards.

Some say, use pva and the pollyfilla then sand and PVA again. Others say just
use plaster.

Not sure what to use for the best.
https://www.homeownershub.com/img/h9
https://www.homeownershub.com/img/ha
https://www.homeownershub.com/img/hb