Given it is a "Variable" flow pump, one can choose any flow rate they desire to get any effect they want. But you are correct in that low flow rates may not have the best skimming ability but then again, for some, that may not matter much. This is one of the reasons some people will run their pumps at higher speed for part of the cycle and low flow rates during other parts. Automatic cleaners may also benefit some with higher flow rates.

Although I have only a two speed pump, I run at full speed for solar and at least a couple of hours a day for skimming and the vacuum cleaner. The rest of the time is low speed. But doing just that saves quite a bit of energy and well worth a two speed pump. A VF should be even better.

Every pool is different and the settings you use for your pool should be taylored to your unique conditions.

mas, well put. At this time of the year we leave the solar cover on until just 1/2 hour before our afternoon plunge but even given our 1 hp pump not all of the flotsam reaches the skimmer

However earlier in the summer that period was three hours, better but barely enough, and so I am curious whether other users of the vf have experienced the difficulty I envision