I agree that this would be excellent experimental data to obtain. However, that is a very difficult experiment to run in the real world.

Even two similar ponds on the same property would probably have different circulation patterns so the temperature profile for the pond with bottom aeration might be affected by other factors relative to the pond with aeration 6' off bottom.

Also, I would think that "time of year" should be a significant factor. The peak average air temperature for most of the U.S. comes at roughly the last week of July to the first week of August. If your pond is already within a few degrees of the "danger zone" for your fish by the middle of June, then I would switch to aerating only at night because that pond has six more weeks of projected warming.

I guess the best experiment would be if someone had two side-by-side "roller pan" forage ponds. Maybe they could run the experiment for the forum.

I do like your question and thinking. Maybe the forum experts should give the advice that if you do experience a summer heat fish kill, then you should immediately run out and measure the temperature profile of the water column in your pond. That would then give people an idea when they are approaching the danger zone in the future for their particular pond and fish population.

Likewise, if you see a large rain event in the forecast, go to the pond and get a temperature profile. Then if you suffer a cold rain induced pond-turnover fish kill, you might know the temperature profile for when your pond is most susceptible to that problem.