I’m thinking about self hosting my photo library, do I have to keep it up-to-date constantly to keep compatibility with the android app?

I would love to know your config so I can do the same.

I agree with the first part, but knowing about bootloader and flashing rom to a new phone is hackerman level, not a regular tech-savvy user.

New generations having hacking skills is more like a cyberpunk novel, reality is lower attention spans, worst reading skills and over-simplified UIs. People gravitate to the simpler way.