Keep the actual epubs and search in those? (You basically want a transcript of a read out book…which is the book itself.)

Needs serious market research to not flop out of the box.

What is the aim? People who want to get into it, but does not know how, or experts? Think half of the attraction of selfhosting is the diy aspect.

What extra would this bring if people can just buy the parts cheaper?

And for those who only want the out of the box experience why would this be better than, let’s say a beestation? (Yeah price, I know, but you obviously would not have the same support level.)

Don’t let it out onto the net…

You can try for linux: https://hub.docker.com/r/tessypowder/backblaze-personal-wine

Here is a controversial thought; do you need to replace the 4?

Just copy to the reader?