Koreader on all devices synching highlights, position, etc..

[nuovodna]

Hi, I've been trying for months to find a solution to make Koreader work between all my devices (iPhone, Windows PC, Linux PC, Kobo Clara BW) but I can't find it.

I have a Raspberry Pi 5 on which I installed syncthing (also on Kobo) for file synchronization.

On the RPI5 I tried these ways:
-) "docker-koreader". I exposed the service on the web and someone entered my server running a script in the container to generate cryptocurrencies.
-) "koreader-novnc" but I can't get it to work

Is there any other way to read also from devices that don't have koreader (iPhone, windows) and sync all the metadata?

I'm currently using "calibre-server" to read on devices without koreader but clearly there is no bilateral synchronization of highlights and progress.

Should I give up or is there a solution?

Thanks a lot!