First off, this program is a God send, so great work!
I have searched this site and read many pages and cannot find exactly what I want:
I'm using v2.36a, which I believe is the latest...
Ultimately I need to be able to include the Length value in the Export function, and see in the tag panel (not as important as being able to include in Export).
When I add tags, (Time or SongLen), close and reopen Mp3tag, there is nothing listed in those added fields on the left-hand side tag panel when I select songs (i.e. - everything else changes accordingly 'Title, Artist, etc...' but nothing appears in the added fields.
I'm assuming that track time (Length) would not export for all tracks either.