An alternative is to use Polycell deep gap filler (UK). To apply, put a small amount into the holes, spray with water then spread with a plastering float. This has the same effect as plaster in filling the area you are trying to fill.
References :
Experience

Make sure the edges are clean and kept clean during the filling. Let it dry then rub a wet sponge over it before trowelling it smooth.
Always scrape the filler flat around the edge so that can always see the surrounding paint edge. Don’t worry about the finish until after it has gone off.
References :

Buy a 25kg bag of finishing plaster (£3.40) you will have loads left over, but might need it if your first try or two is not good.
you need a mixing bucket and a mixing paddle that connects to your drill. a plastering trowel an old board to dump the mixed plaster onto (spot in the trade) and water.

Have fun.
References :

"Spackle" or similar in brand name of substance is fine up to a depth of 1/2 inch. The problem with any water based material isn’t in the application; it’s in the drying process. At certain thicknesses substances such as those tend to crack in the final stages of drying; if applied too heavily.

I’d suggest a pre-mix in any case; and sanding certainly; if neccesary.

Steven Wolf

It’s possible there are poly blended substances sold; that are less prone to any OOOPS.
References :
45 plus years as a contractor