I must be doing something wrong, I really like using the USB for my music source. The only time I had a problem occurred when the playlist had a misspelled word or wrong key stroke. That messes up the whole Apple Play system.A few problems I have with my 2017 when playing USB media:
1. Shuffle issues - "shuffle" shouldn't play the songs in the same order every time! I have shortcut buttons set by genre, and every time I click on it's the same sequence of songs.
2. Additional Favorite Options - would like to be able to create favorite for a folder, or for "All Music".
3. A way to pick a favorite shortcut from the steering wheel. With radio, you can change stations with the steering wheel, but once you select USB media, the steering wheel control is used to change songs - to change to a different genre, you need to use the touchscreen.
4. A way to rate, flag, and/or delete songs. A really annoying song found its way into one of my folders, and I kept forgetting what it was so I could remedy the situation when I got home.
5. Auto-volume - not sure if this is supposed to correct volume differences between songs, or automatically compensate for road noise, but it doesn't seem to do either, and I have it set to "high".
I wasn't aware there was a shuffle play option, I'll have to look into that. BUT then again, I have about 15 play lists, dividing the generes, books, pod casts, so shuffle may not benefit my situation.
FAVORITE OPTIONS.... If I understand what you want to do... it all has to do with the play lists.
My play lists are made up by Genere, oldies 60's, oldies 70's, Elevator music, Ambient Music, Audio books, etc, etc.
NOW if you want to be able to select certain Genere, or songs, Or select playlists by a button, you can program what would be a radio preset button. After the selected song plays, then next in the play list plays, and so on. This is very convenient and I was surprised to find it operated this way.
EDIT- So I took the volt out to from here to there, I located the selection for SHUFFLE. So it works, but I was warned that the Controls for USB were not very complex and just performed simple duties.
For EXAMPLE: If you have your Generes in separate folders, they play inside that folder if on a playlist. If you select a song in that folder and select SHUFFLE, the control will shuffle between all the folders and not the selected one. -END EDIT
If you just want to play all music, then don't select the playlists, it will play, sorting by alpha-numerically througout all the folders, and will not reference the playlists.
Not sure what your volume thoughts are, the steering wheel does allow volume adjustments.
The Apple Play system with the USB filled with music and play lists BLOWS AWAY the old CD MULTI CHANGER.