Some past versions of dBpa could batch convert the files referenced by an M3U playlist.

Subsequent to the removal of this feature, the only workarounds I know are to select the files manually in the batch converter UI (could take hours) or to use another program such as MediaMonkey to copy the files from the playlist to a temporary location and convert from there (can take a large amount of disc space).

Please restore the ability to accept an M3U playlist!