@tim-moody: expanding on Line 7 of /etc/systemd/system/kiwix-serve @jvonau, @deldesir and I are curious if you think the following might work:

kiwix-serve [...] --library /library/zims/library.xml /library/www/html/local_content/USB*/library/www/html/*.zim

Another equally effective approach could be:

kiwix-serve [...] --library /library/zims/library.xml /media/usb*/library/www/html/*.zim

...to load temporary ZIM files from teachers' USB sticks, after "systemctl restart kiwix-serve" [would be] triggered by usb-lib of course, upon insertion (and upon removal?) of any USB media.

An alternative approach might be to auto-display ALL ZIM files on USB sticks/drives inserted in IIAB?

Either Way: building upon teachers' requests to have more tactile/immediate control of their own content — directly in their own hands — as we've begun to offer here:

http://FAQ.IIAB.IO Item 4 = "Can teachers display their own content?"