This is more of a general question than a problem.
I want to add a hardware button to shutdown the pi using GPIO, and a LED to indicate it's status.
I've found some ideas on how to do this.https://embeddedcomputing.com/technology/open-source/development-kits/raspberry-pi-power-up-and-shutdown-with-a-physical-button
This requires some system configuration, He proposes two options either a crontab entry or a change to to /boot/config.txt. it's really not anything to do with octoprint, but I'm trying to wrap my head around how to manage the configuration without interfering with octoprint or updates.
One option might be for me to write a plugin which manages changes to the crontab or config files, but that's feeling a bit like overkill to me, maybe not.