Yeah I understand that, but playlists can be created and edited extremely easy on a smart phone with the build in music apps. There's just no need to fuss around with this complicated m3u technique anymore as better and easier alternatives are available.
I just use Spotify and bluetooth to play my own playlists I've created. As Spotify Premium is cloud based (but playlists can be downloaded locally too for offline listening) all my songs and playlists are synchronised across all the devices I own
