Still reading through all the stuff you linked. I came across this:
https://developer.puri.sm/Librem5/Development_Environment/Phone/Connecting_via_USB.html
So, since all I’m doing is a USB tether between the Librem 5 and the desktop computer, shouldn’t I see something happening on the desktop computer? But when I run the lsusb command in the terminal of the desktop computer while the librem is tethered, it does not see the librem. (I’m just trying to see how to get this tethering to work.)