What product is that? It looks like lime render with formed corners. Was the house stone originally?
If they've done that over block that's wild unless you wanted it not to look modern and wanted a cottage look?
It's a strange one
Obviously the rendagrip manufacturer won't stand by going over painted substrates there's too many variables and you'd have clowns trying to sue them after rendering over flaking paint. Grind, wire brush, jet wash and whatever paint is still on the wall rendagrip over that.