2 years ago I painstakingly painted my knock-through living room/dining room in standard Dulux Jasmine white. I am extremely proud of the level of finish I achieved (this is relevant, not just a boast), with no roller marks or brush strokes!
The walls are still in great nick, but they are about to be wrecked by building work through lath and plaster walls. There is a plasterer on hand to make good.
When I repaint, I'm going to use Dulux Trade Diamond matt - same brand, same colour, different type of paint. Can I just hoover up all the dust, sugar soap down the existing walls, and overcoat, or do I need to do the full job of sanding down and repainting? Will the new paint take OK if I do minimal prep, and will I get a great finish again? (There is almost no filling to do as the walls were fresh plaster 2 years ago and there are no cracks).