16 shares total.

Wait a minute! Given how resource constrained S1 devices were, someone though that the limit should be 16? Surely a smaller number (eg 4) would cover 99.99% of use cases and save precious bytes in the flash of every speaker. Curious decision.

I don’t think that there would be much of a difference. Given that one must supply the complete file path name to the NAS, the drive and share names could be stored as a token and 16 possible tokens would require only a single byte per track.

You can always add an SMB gateway and combine all your shares (SMB or not) into a single SMB share to pass to Sonos.

SMB gateway on a Raspberry Pi, should work elsewhere as well.

SMB v1 Gateway

And who needs more NAS dives when there’s stil a 65k limit?

Fitting on a NAS is not likely to be an issue. Still...

His and Hers music collections that are also used on non-Sonos gear?

Kid’s collections they can edit while keeping your music safe from grubby little fingers?

Over the track count or meta-data limits might be worked around with multiple collections. Only power up the one you want to listen to and reindex. On a SSD based NAS that is pretty fast.

In my situation I have my dedicated Pi based Sonos NAS with all of the music I’m happy with on it. A second “working on it” NAS where I put music I’m working on, (directory names, track labels, meta tags, encoding) that is shared to the Sonos. Once Sonos is happy with it I move it to my dedicated Sonos NAS.