My SubSonic server is on a headless Win10 box. Automatically exporting playlists (static and auto) whenever there is a change works, errr, automatically. I don't have to do anything. SubSonic points to the directory in which the exported playlists live and I'm off and running.
I'm confused about your use of "change" with regard to auto-playlists.
For all my auto-playlists, they're set up and done. I never add or remove anything from them, they refresh (change?) with new lists when I click/open.
The way I understand checking the box works is the currently displayed list is exported and subsequently updated lists are saved each time I returned to the playlist, which means the only way to refresh (change?) the list is through MusicBee.
This would fall outside my desired use case with SubSonic. See below.
With BubbleUPnP connected to the MB DLNA plugin, wouldn't you be able to load your MB playlists, including the auto-playlists, from the phone? Or are you trying to avoid using that plugin?
Both the BubbleUPnP app and the DLNA plug-in work exceptionally for me when I'm on my home network, but when I'm not home and listening through a mobile device, I can't perform the "auto" part of auto-playlists unless my desktop is on (I don't leave it on 24/7 anymore) and MusicBee is running. The alternative, I suppose, is to install a web server that has its own smart playlists function, but I doubt I could tune them using the same level of detail I can with MusicBee.