It would appear that I've stumbled into a pre-existing and ongoing disagreement about using SpyderUtility and using a screensaver, which wasn't my intention.
For the record, I plan to continue running SpyderUtility (because of the known tendency of the system and other software to mess with the LUT), and I plan to continue running a screensaver (simply because I'm old-fashioned and I like to watch them ).
Can anyone tell me anything about those SpyderUtility preferences which were the basis for my post?