That's not the point. Maybe you can, but for how long? you will never stop asking the question with docker...

Ok, I have a web browser on a locked down device and nothing else: how do I print a pdf or a photo using IPP?

I have: a camera, a browser, a file manager (kind of, think of an iPhone or some stock android business device) and I need to print a photo taken with the camera or a pdf file sent to me via email or WhatsApp?

The device is connected to the WiFi guest network with limited internet access (if any) and as only available service a server with port 443 open (a reverse proxy on that, captive portal and such).

In my experience, there is no way to print via cups in this configuration. Maybe I am wrong?

LOL

Indeed you are, but if you release it you probably want people to use it, otherwise why release at all? Going github/gitlab way just make that easier.

You are free to do what you want ofc, just my thoughts.

Did I? Maybe because I am not an English speaker? Good to know tough, I went by instinct

I have read that kopia has corrupted Dara systematically in the past. What's your experience with it?

Restic has a neat web GUI called Backrest

Restic or Borg on your side, a safe and remote destination on the other side.

use restic, with backrest web GUI, and cannot be happier.

As for remote site, I use a remote machine I rent, but there are plenty of providers around, shop a bit... Or find a friend for reciprocal backup?

Synchting is the way... Been using it since ever. Easy to setup, works flawlessly, doesn't get into the way.

I use it for server, PC, laptop and android devices.

... Then you want to backup (Borg, restic...) your synched files of course ....

I settled with silverbullet.md self hosted, plus native editor on android, and synchting to keep stuff up to date.

Over 4g or 5g there is no way to use private trackers you will always be a hit and run.

It seems you can pay with amazon UK gift cards