I have synced about five playlists to a micro thumb drive and set MediaCenter to create playlists at root. All the different flavors of playlist. My head unit did not recognize any playlists. Only folders.
From page 32 of the manual:
REFERENCES
Playable files
• Playable audio file:
For disc: MP3 (.mp3), WMA (.wma), AAC (.aac)
For USB mass storage class device:
MP3 (.mp3), WMA (.wma), AAC (.aac), AAC (.m4a), WAV (.wav), FLAC (.flac)
• Playable disc media: CD-R/CD-RW/CD-ROM
• Playable disc file format: ISO 9660 Level 1/2, Joliet, Long file name
• Playable USB device file system: FAT12, FAT16, FAT32
Even when audio files comply with the standards listed above, playback may be impossible
depending on the types or conditions of media or devices.
The AAC (.m4a) file in a CD encoded by iTunes cannot be played on this unit.
No mention of any type of playlist. In fact, searching the manual for the keyword "playlist" only return playing Spotify playlists. Searching for ".m3u" returns nothing. Sure, I can play playlists synced to my phone over bluetooth or over USB. I don't want to do that. I have a 256 GB thumbdrive specifically for music in my car for this stereo to always have music playing without touching my phone, wondering about it's level of charge, or even having it on me.
What you're describing is not my preferred method of consumption. Hence my feature request. I've paid for JRiver MediaCenter and have kept it updated for years, and I would very much like to fit it into my own workflow. I only ask for a simple feature that other music management applications provide. MusicBee, Mediamonkey, and Helium Music Manager all support this.
I didn't think this was a big ask, but it kind of breaks MediaCenter for me.
I've tried ways around it:
Setting up an external device in for each playlist folder in MC which was too unwieldy with tens of playlists to sync to one thumbdrive.
Using third party software to rearrange the files on the drive after MC synced which didn't always work correctly.
And finally, moving to MusicBee, which, in this regard, works flawlessly. MusicBee has other shortcomings, which unfortunatey, are baked into the core of that program.
I really don't want to sound like a jerk here, but "It's JVC's fault" sounds weak for a feature request (yes, I have posted this in the MC 26 feature request thread). I really want to move back to MC, and keep paying for upgrades. I really love the power of the expression language, and what it's capable of, but I've spend countless hours collecting thousands of CDs, ripping them to FLAC, and meticulously correcting the metatdata, to just be told I'm doing it wrong.