Yours seem to be set at number 3 preload (out of 5 possible positions). So yes can be reduced 2 stops.
Mine look exactly the same except not black springs. I also have castellated rings at the top, but not thick like yours, more like thin plate. I don’t think they can be rotated or any kind of adjustment, I think they’re just anchors or stops for the tops of the springs. Probably can be removed if spring is compressed.