Since your first inquiry to this topic, ...
Mp3tagSplitLyricsList
... about a year ago, there is nothing new.
Read there ... how the Mp3tagSplitList tool works ...
Mp3tagSplitLyricsList
After installing ... try out the offered example Mp3tag export ".mte" scripts, ... they should be listed in your Mp3tag Export dialog.
At first you may have a look into the ".mte" files and their coding, ...
and decide which one could be used right away, ...
or perhaps has to be adjusted to your personal needs.
Try out the work routine with a few files, which have a tag-field UNSYCEDLYRICS filled with any text.
DD.20150208.1317.CET