Lets see a show of hands of people that assume that the majority of O2 that enters a pond from aeration comes from the bubbles that the aeration system brings to the pond.
Winter aeration is different than summer aeration. Different goals and different methods to achieve those goals.
Winter aeration for ponds that have a heavy snow/ice cover is different than winter aeration for ponds that get 1" of ice on it for 3-4 weeks of the winter.
During winter in cold climates where ponds freeze over, you do not want to aerate the lowest region of the pond anyway. Water is densest at 39°F, and aerating the upper 1/3 of the water column allows the bottom of the pond to stay as a warm water refuge for the fish. Trout can survive in much colder water than RES can.
This is where the different geographical areas of the country really point out the differences in pond management strategy.
I agree with DNickolaus, that under aerating could create a lower water quality in the whole pond than if the pond was not aerated at all.
