Just train them to use the computer for Powership or internet labels...
tell them it saves them time and money.
I had a heavy pup route once, when I started it, about 1/2 were still using airbills.
when I was done, only 2 wouldn't use the computer, mostly because they didn't have reliable
connections at their "home offices"
Also another tip if you have dropboxes(you may know this already) you can open the box early
and start scanning, just don't scan that last package before the ready time. then you are good to go. Also don't scan a ground package at an early opened dropbox it'll nail you.(yes we can scan them under exceptions, but I don't think the scan actually does anything)