Sonos does not currently have, as a regular operating feature, the ability to sort songs in a Playlist alphabetically and then return to the original sort order. In my opinion, this would be extremely valuable for the following reason: if one likes a particular type of music, e.g., 50's Doo Wop, and creates a playlist with multiple albums that are collections of Doo Wop songs, there is a problem - numerous duplication of songs. If one could sort the collected songs alphabetically, it would be a simple matter to go through and weed out all the duplicate songs. The same problem of duplication exists if one is creating a Playlist for a particular artist which includes both studio albums (which are ordinarily not duplicative) and collections for that artist drawn from various studio albums or live performance albums. With alphabetical sorting one could easily eliminate the duplication of songs.
I have contacted Sonos requesting that this feature be made available. If you agree that this would be worthwhile, please contact Sonos' Technical Support department and let them know that you would also support having such a feature available as a regular part of the Sonos operating system.