>>1592787cup-cone basically is just one end is a cone and the other end is the inverse (cup) which automatically aligns the pieces; see pic (the cone), the ones you posted don't quite seem to be the best shape for this as there's no cone shape, but maybe it will work with more frustration on alignment and setup. The cone just kinda handles that all for you and is more consistent
I forgot about that left side knob thing but yes it can be used for some adjustment but I'm not sure what the range is