When I installed the VF, I determined what the optimum RPM/GPM would be in regards to power use vs water clarity. At 350 watts, it's running about 1200 RPM (IIRC) and is really in the sweet spot. I believe the higher power usage currently is due to some changes I made in the eyeballs, but even at 450, it's not terrible usage. The SWG is running 22 hours per day at 90%. It was simply easier to let it go ahead and run 24/7 with it set up this way than to go through a bunch of trouble fiddling with the pump's programming and the SWG to find the absolute optimum run time by shaving 2 hours off.
Another issue is I only have returns in the shallow end and one skimmer that's not really in the optimum location. Also, I have lots of very large trees. To keep the pool clear of leaves, the longer run time helps to catch them in the skimmer before they go to the bottom. I guess not as much thought went into where returns and skimmer(s) should go when they built this pool. Currently I have slit eyeballs in 3 of the returns, and a PoolSkim on the 4th, to assist with the problem. It seems to be working.
If I ran the pump for 12 hours, I would have to use more power and a higher GPM. Twice the power does not equal twice the GPM, so really there is no savings. In fact, it could cost me more.