Something good's been going on, and I can only guess that the Sonos servers have had some sort of upgrade in the last day or so.  My PC apps (S1 and 2) have not changed; my Adroid S2 has been upgraded but S1 has not.

My software is now 
S1    Android & PC 11.14, B 572150280.  Speaker firmware 11.14, B 572151190
S2    Android 80.09.04 20240917-6a714567   PC 16.3 B 80155014  Speaker firmware  16.3.3 B 80156190.

There is some really good news for Android users - at least as seen through my system.  Here's what I am now finding:-

1.  S1, both Android and PC, can now connect to and index my local library on a Synology NAS, neither of which which was possible last week.  S2 has always been able to do this.  The NAS runs SMBv1-3.

2  S1, both Android and PC, can now see and display all the Album Art in the library. S2 can see it on the PC but still not in Android.

3  S1, both Android and PC, groups Albums correctly.  S2 continues to fail on this.

While there is still a way to go with the S2 App, it is clear - at least to me - that there is real progress being made in restoring some of the features lost in the May "upgrade".  I take my hat off to the developers who are battling on to unravel the mess and whose efforts deserve sincere appreciation.

I have discovered all this in the process of downgrading my system to S1, which has been successful except that I have been totally unable to downgrade my two Fives, which are now all that remains of my S2 setup.  Has anybody been able to do this with Android software?  The Windows app doesn't have this function available so I'd love to hear from anybody who has done it.