You'll have to remove the file from the device to have it Synced again.

I have tested with MMW5 but that also does not resync the file, but only changes its metadata information in the android file system directly - which from a performance point of view is obviously much faster and still correct.

Nevertheless, for my particular problem, are there any actions or modifications or database field changes that I could perform to cause MMW to provide the full file again for resync?

Sorry for the late response, work work work. You are right, I am only on the latest version of MMW4 and haven't checked if the same behaviour happens with MMW5, mainly because I never made the complete jump as I was so used to my "workflows" in v4. I will try again.

You may want to start with updating to the latest release of MediaMonkey as there are many Sync improvements.

So far I tried modifying some metadata like the field "user def 1" (don't know the exact mp3 tag name), which is sth I could do on large amounts of files without corrupting any other meta data. This would not cause any re-sync.
That's why I asked which actions would definitely trigger a resync.

I haven't yet tried to fiddle with the database like regexp any timestamp field.

If a file has been modified in MMW it should re-sync to MMA. Are files not re-syncing?

Hello,

which modifications on the media file or metadata cause MMA to trigger a resync/re-download?

I have changed some basic volume gain settings in the sync settings, and would like to resync a very large number of files (probably from the last two years), but would rather not just delete the whole SD card directory on my phone which would result in an even larger resync (130k tracks).