Over the past few days, I’ve been mulling over just exactly why I had defined any locations. When I deleted them, I thought only about the fact that it had been many months or perhaps years since I’d last used the Network Locations facility to change my network settings at all — and since it was clear that I wasn’t using them, and since I had good backups, I just went ahead and deleted them without looking into how the settings might have differed among them.
Coincidentally, I just tripped over my own comment to a post here, which makes it all clear. It was to work around a Monterey bug!
There’s a lesson here somewhere…