"using sessions" + exporting and importing kate's configuration file ...

 You can import multiple files while starting up kate:

 kate "file1.txt" "file2.txt" &

 I am also trying to get a way to export/import a configuration file,
but the documentation I have checked:

 https://docs.kde.org/stable5/en/kate/kate/fundamentals-using-sessions.html
 https://docs.kde.org/stable5/en/kate/kate/kate.pdf
 https://docs.kde.org/trunk5/en/kate/katepart/katepart.pdf

 doesn't quite specify it and some google searches didn't show this to
me which I think should be trivial. All I found was:

 kate -s --start name: starts Kate with the session name . The session
is created if it does not exist already. If a Kate instance running
the specified session exists, the specified files are loaded in that
instance.

 I don't see how you could import a previously saved session to/from a file.

 use case: you go into exposed mode (access the Internet) using a Live
Linux DVD (say Debian or Ubuntu) on which kate isn't installed, but
you shouldn't have to access the Internet and go every time:

 sudo apt-get update
 sudo apt-get install kate

 you would just install it with its corresponding package dependencies
which you keep locally ... Then you would need to go:

 kate --start <wherever directory and/or file> --use-config <config file> &

 How can you do that?

 lbrtchx