Dramatic Heat Dissipation drop on SoZ

Has anyone experienced or noticed a difference in heat dissipation with their SoZ when wired in singled ended vs. balanced configuration?

I had just rewired my SoZ to balanced XLR mode for the 1st time and can't believe the huge drop in heat dissipation compared to when i had it wired in single ended RCA config.

My SoZ does 25w x 2 so the difference may not be noticeable for small wattage SoZ amps?
 
Speaking of single ended and balanced ......,
what harm would it do to the power amp if one forgot to install the shorting clip across the balanced input when the single ended input is used on the power amp? Eveything works except that there is a pretty loud humming noise at the background.
I have stop doing that after I remember to use the shorting clip.