Couple things that may help your discussions with The Minister of Finance.
My airline has been 100% overland since I installed aeration. I ran a shallow diffuser 24/7 last winter. Zero freeze-ups.
Aeration is not going to cool the pond during swimming season. Very likely it will do exactly the opposite.
When we were stuck in the middle of that 100° crap a couple or three weeks ago the surface temp in my pond was 88.7°.
10' deep the water temp was 80.1°.
