Great, thank you !
Actually I recognize I would shoot more for @sicro’s solution than @4world’s request, the reason being that most of our users are connected to a server that we provide, with synced folder, so the “not connected” use case would not apply. And … maybe native OS features support that (would love to have a list of the Windows and Mac OS either native or free/OSS tools that do versioning without a installation hassle for mass users).
SO I understand from @AudriusButkevicius’s comment that it’s already supported, only cosmetic changes like enforcement of consistent folders settings would be required to prevent this use case to be broken by wrong stversions folder names, or wrong ignore rules, or conflicting versioning strategies.
That could actually even start without developement, just with a guide or tutorial how to configure settings to support this:
stversions is just a directory, you are free to add it as a syncthing folder and share it among your devices.
and this:
Not really, as these are independant entities. New versions or version deletions does not mean new files in the parent folder