Please add a way to sync the full metadata using iCloud or cloud storage like Google Drive. I am sure most of us have no problem buying additional storage because I have 50GB in iCloud that I can bump to 200GB if I need it. I also have unlimited google Drive storage as an alumni for my school and 100GB for gdrive is pretty cheap anyways.
It really sucks to have to load the metadata from scratch for each iOS and tvOS device you use. Also google Drive has an api limit for scraping and when the metadata takes too many hits on your gdrive it bans you from using any service that uses the api or from downloading large files. It would be better to just sync the current metadata for your collection from iCloud or another cloud storage.