I never found that, it is a great question!
However I managed to learn if / when “Location” was from a reliable source with the install of MyLocation, https://github.com/mirfatif/MyLocation – com.mirfatif.mylocation
My Location app shows where various “current fix” points to; this can be copy and pasted to Notes, or my best choice to Magic Earth. My copy of Maps has 
(a folder of Favourites) in all the plots I got from Network Location, GPS (and from the “old days” NLP Backends – the closest to true “Home” (after GPS on a good day) on my map is the old AppleWifiNlpBackend .)
I eventually decided to stop the use of MLS due to stability. Regular fixes, 3 different at 1 mile radius and 1 at 3 mile radius, still produced (only irritating) different weather predictions (English weather!).
Some apps do benefit from Network Location, where for instance Network Location is used to pull up the correct map, then GPS takes over after an interval as Memory Map for All quick test here.