Happy, I am, that you found this useful, Fex.
Thanks again to Brian blgentry, who gave me the magic keys to Android happiness with MC.
Since writing that post, I have found that my HTC One M8, and probably other Androids, duplicates the Playlists that I upload to my phone's SD card.
Use the approach outlined above, I upload my Music and Playlist folders and files to my SD card on my HTC One M8. My various Android Music apps continue to work fine. However, my phone automatically copies the Playlist folder from my SD card to the phone's internal drive, in the music folder. In my Music apps, I then see two of every playlist I own. Both seem to work. Nuisance, it is, but not fatal.
I've deleted the internal drive copy of the playlist folder that Android automatically copied and it magically reappears. I've also tried deleting the original Playlist folder that I loaded on the SD card and it stays deleted. No problem, just a weird behavior.
All in all, this approach to managing MC music on my stubborn HTC One M8 Android still works beautifully. The only (minor) catch is the extra Playlist folder that gets copied onto the phone's internal drive. I'd delete it when updating your Playlists, just to be safe.
Maybe others see this behavior. Glad I was of help. Thanks, again, Brian, for the keys.