It’s very easy. It can be done through calibre, yes, although I prefer self-hosting a library that the kobo syncs to. I’ve used Calibre-Web, and recently moved to BookLore, and the latter is really, really nice so far. I have three people set up with their own accounts on BookLore, and we share one general library, but each person also gets their own personal library to do with as they please, and each person can choose what they want on their kobo, and it all syncs just by hitting the sync button on the kobo (you point the kobo to your own “store” instead of the kobo store). If you want to keep the stock store with the ability to also load “alternatively sourced” books, that’s also easy with OPDS, also supported (very well) in BookLore.

Kobo can also be pretty customizable too, for what it’s worth. KOReader is highly customizable, but if that’s not your jam, there’s also kobopatch which can change the default OS to some degree. Also NickleMenu, NickleClock, etc. There’s plenty available to tune a kobo, imo, and I’m someone that’s generally very “tinkery” with stuff.

Heavily leaning this way, thank you for another vote!

I sometimes travel for work, as an example, and need to be able to access things to take care of things while I’m away and the girlfriend is home, or when she’s with me and someone else is watching the place (I have a dog that needs petsat). I definitely have the time to tinker with it. Patience may be another thing, though, lol.

The more replies like this I get, the more I’m inclined to set up a second computer with just TrueNAS and let it do nothing but handle that. I assume that, then, would be usable by the server running proxmox with all its containers and whatnots.

Thank you for the input!