Just to add: It's definitely a bad practice to never update your images, because the docker images and their base images will accumulate security holes. There aren't many solutions around for automatically pulling and running new images.
Isn't that exactly what watchtower does?
https://github.com/containrrr/watchtower
It works great on my mediacenter server running deluge, plex, sonarr, radarr, jackett and OpenVPN in docker.
My server was much more stable after it didn’t try to update all the time any more.
I wonder if I can set a minimum timeout.
Then again, Harbormaster doesn't do that either unless the upstream git repo changes.
I want to "read all available updates" at my convenience, not get alerts reminding me to update my server.
Maybe I need to write some sort of plugin to DUIN that appends to a text file or web page or SQLite db... Hm.
Personally, since I’m a big fan of RSS, I’d set up email in Diun and send it to an email generated by https://kill-the-newsletter.com/