I am accessing files remotely from within Emacs through Tramp over mobile Internet.
I just remembered, how many file checks Emacs’ VC library does, if you don’t cut down its list vc-handled-backends. For every single backend listed there “we” are doing a “repository check”. Maybe that’s fast in a LAN, it may even be rather fast on a WAN, but you don’t really want to waste the transfer volume through all these checks, do you?
Customise vc-handled-backends the Emacs way, and you will sleep better.