Wow....I have over 10,000 hours in 737's and I thought they just meant when you have no flaps out the power required to maintain V ref is very low so use caution.
Don't over think it. It ain't that hard.
The ref speeds you are bugging for should be for the flap setting you are using to land. I see no need to bug for any other flap settings. Use 210 to manuever unless your over 117 K and then use the 220 number. It has proper buffet margins in both cases.
Simple enough?