Ultrasonic washers and softer sound?

This topic has been visited multiple times. I purchased a KLAudio washer system (external reservoir version with inline continuous filtration) and the silencer case this past July. I am just now at a point, after about 400 washed albums (that count includes some that required multiple passes) where I feel I can intelligently speak to the efficacy of this technology.

Does it work? Absolutely!!

I had one album that sounded really nice with my MC Anna and Anamighty Sound modified 103r (103.3) but would exhibit two nasty skips with my London Reference. The washer completely eradicated one of the boogers, but the other was persistent even after 2 more wash cycles. I then broke out my Disc Dr. manual system and cleaned the offending side of the Lp. Played it and the skip was still there. I thought it was actual physical damage but decided to put it in the ultrasonic one last time, that did the trick, plays like there was never an issue. Ninety nine percent of the time, all I need is one wash via the KLAudio and all is good.

The point of this thread is that I have read where some have claimed after using an ultrasonic washer the music sounds less airy. I have had this occur exactly once and I think I know the culprit. In my case it would not be chemically related as the KLAudio uses only distilled water. One day I was listening to a few albums that had not been initiated in the U.S. bath so I washed quite a few back to back. I noticed an album I was quite familiar with sounded soft and kinda dull after a wash (I did play it before the wash to have a before and after impression in my mind). I was a bit confused as I had not noticed this effect with my previous washings.

I also noticed that I could hear the fan on the external radiator used to cool the water in the supply tank running. I grabbed the side of the tank and sure enough the water was heated enough that I could easily detect the heat with my bare hands. I posited that the heated water softened the vinyl hence yielding a softer sound. I allowed the vinyl time to cool and then replayed the same track. Everything was tight, airy and back to normal.

Even though my system has an active water cooling system, said water still gets warm if I wash around five or more records back to back. I have learned to simply let a record cool down for about ten minutes if the water is warm during a wash cycle.
I have experienced this dulling of sound only that one time and I am relatively sure that the heated fluid is the culprit.

Has anyone else noticed this effect after washing a number of records back to back and having the water somewhat heated?