[calibos]

I'm about to move from a pair of ancient DLink DNS323 Nas boxes to a DIY Media server running Win10 and Stablebit Drivepool and Snapraid.

I'm also running 6 Kodi clients on ancient Arctic MC001 Atom powered boxes that I can't afford to replace for another while and they are painfully slow rescanning the library.

I remember investigating shared library years ago and it used MySQL and looked very complicated to setup, my Nas boxes couldn't run it and I didn't have a 24/7 Windows Kodi Client so long fingered the idea.

Just wondering given I will soon have a 24/7 Windows Media server, is the only library sharing option still MySQL or is there now an integrated solution in the latest versions of Kodi?

[Klojum]

is the only library sharing option still MySQL

Yes, MySQL is still (for 10+ years now) an experimental addition to Kodi.
Some others use the UPnP option, but option can have IMHO mixed results.

[LongMan]

Media importing and library integration was the future but it seems to have fallen by the wayside.

[DarrenHill]

The best internal option is still MySQL (wiki), but as noted other use UPNP.

Others still use an external solution like Emby, which completely replaces the Kodi database with its own networked set-up.