djay became my main app for the same reason. Unfortunately, making this dream workflow work is a little bit trickier than what I had imagined in the beginning. A few caveats to consider:
- I don’t put my files on iCloud Drive because there is no guarantee they’ll be available offline. There is no way to tell iCloud Drive to keep files available offline so you always run the risk that iOS decides to delete them.
- iTunes Match would be an ideal solution but it doesn’t work the way it’s supposed to, neither in djay nor in general
That left me with option 3, local syncing (via cable or WiFi) of music through Music.app (née iTunes). I create my playlists in Music.app and they get transported over perfectly. This also makes sure your set cue points will appear on all other devices, thanks to iCloud.
Still, there is one caveat that remains: currently, not all settings are synced via iCloud; most strikingly the beat grids are omitted, plus you’ll always have to re-analyze your tracks on any new platform. Hopefully, this will be addressed in the future 
There are a few caveats but I still very much like this setup. Most amazingly, I can now prepare my tracks on the go on my iPhone and later use these prepared tracks on my iPad. 
Hope this helps you!
