Vref30+80 is min clean speed, depending on the phase of flight. And Vref30+100 is a good pointer to engine out speed, give or take a couple of knots.
I personally have mine set to the flap schedule (vref30+40, +80) until top of climb then set Mmo and Vref30+100 for the cruise.
We don't have SOPs on what should be set on the ASI except during approach and take-off, so its down to individual pilots.