SRS.,,,I am looking in.... and I see the ultimate goal(s) of integrating smart phones into the process. Since I don't use one, and have no USB connection in my 2002 vehicle, my only concerns are putting sound files onto my Win7 desktop in an order and in folders that I control.
   I am not quite sure that I understand the problem of getting files (or tracks) into the order desired. If I rip a CD..which is very seldom these days.. I simply designate it's destination. I do have 2 machines that will turn any sound source (including tapes and LPs) into MP3s. One of them will, using Audacity, break files at quiet points of about 3 seconds. (I also have Wavosaur, but have just begun to mess with it. It looks like it would help ME a lot, but it says it's good thru Win 7 and I have no idea if it will works on WIN 10)

   Since they seem to expect audio books to just be played in the order they give you, perhaps it's their numbering system? 1,2,3,4... instead of 01, 02, 03..." In this case a renaming program 'might' help. (There are several other free ones)

Because I am ONLY on a Win7 desktop, I constantly depend on a file manager to move (and rename) files and folders around.My favorite is https://freecommander.com/en/summary/ (both older & new versions..portable and install) on download page).... and if I lose something, but know the name, I constantly depend on a program called http://www.indexyourfiles.com/ to find anything almost instantly.

So... I have no idea if these ideas will help those of you who keep up with the latest gadgets. I'd almost have to see the processes live to have any insights. I have maybe 10,000-12,000 sound and video files on my PCs, portable drives..etc.. but for playing in the car, I would have to burn them onto a CD...and I already have hundreds of music CDs ready. I no longer take very long drives, so... *shrug*

I'll re-read this later and see if I have any insights...

Good luck!