Storage Templates. Photos are stored in subdirectories categorized by date.

CLI Import. It looks like you may be able to import your albums with the cli and --album flag, not sure about exporting though.

If you only need cardav/caldav functionality, Radicale provides just that. Can be deployed as a container and works flawlessly with DAVx5.

It might as well be. It’s a Windows app made by Microsoft specifically for Windows and comes preinstalled. IIRC, you can’t even fully uninstall the xbox bits without powershell or regedit.