The current mobile-to-desktop sync method is garbage. I regularly give up on trying to keep the edits I've made on my mobile device, and just use a third-party app to sync DNGs to Dropbox, then on to me NAS. That doesn't copy the edits I've made because LR Mobile just won't create a sidecar regardless of what you do on the desktop - you can't even force the creation of the sidecars on the desktop.
Thanks, TotallyUnstoppable, for your answer. But, wow, this is not what I expected to hear! It rather defeats the purpose of using LR mobile to capture and do edits on athe fly. From the LR mobile get started video tutorial, it seems as though you can add desktop LR edits to an image first imported to, and then edited in, LR mobile - but in the 'from LR Mobile' storage. Surely this cannot be right, as it counters all normal workflows with structured filing on the desktop / NAS?
maybe someone from Adobe LR themselves can jump in and explain?
Unless I'm misunderstanding something, this should be fairly easy…
Once the files have downloaded to the desktop and appear under the iPad's icon, I create the required folders in my main library's filing structure from within LR's Folders panel. I then just drag the files across into the new folders, again from within LR. This moves the files physically to the new location and preserves all edits originally made on the iPad.