On the rear of my backplate, I have a couple of small pouches into which I can drop a pair of trim weights. They screw to the holes round the edge of the backplate using a couple of those window screws. Very nice they are too. Narked at 60 I think they are. For use on my single tank rig.
Now I can find many of them with the thing that slides onto 2" webbing, but can't find the screw ones. Anyone seen anything like that? I suppose I could bolt a couple on using stainless screws but that's not the point.