I'm sharing this easy solution after wasting a couple hours figuring out what's going on with the Professional Print & Layout software. Whenever the IP address of my printer changed (due to a router reboot, power outage, etc), all of my presets would stop working, and the print queue would be unable to send to the printer. Rather than wasting time creating a new printer and then editing or adding presets back, I wrote a simple zsh function for macOS that just updates all of Canon's .xml files to change the printer's address on-the-fly.
Using Terminal, paste this into a file named .zprofile in your home folder:
function printerip { pushd ~/Library/Application\ Support/Canon; find . -name "*.xml" -exec sed -i '' -e "s/$1/$2/g" {} \;; popd }
Save, then run the command "source .zprofile" to source in the new function. It will also be there whenever you start a new shell. To use it, just type "printerip <old ip> <new ip>" and hit enter, for example:
printerip 192.168.1.18 192.168.1.23
You can now update all of your presets and printer profile in a couple seconds.
