I tried this using John Melas’ tools and had a problem.
When I opened up the .all file from the Motif Rack ES Total Librarian with the Motif ES version of Total Librarian I got the expected message about the file being coverted from one format to the other (John told me it would do this).  But after the conversion, there was nothing in the Performances folder.

Then I imported all the banks from the ES8 into the Total Librarian, and opened that .all file in the Rack ES version of Total Librarian. Got the expected message about converting the file and, once again, nothing in the Performances folder.

I tried using the Performance Editor and was able to load Performances created on the Rack ES into my ES8, but found that Part 1 is always silent.  Parts 2, 3 and 4 sound fine.  I tried loading a different voice into Part 1, and also using the Voice Copier feature to copy a voice into Part 1, but couldn’t get any sound from Part 1 until I re-initialized the Performance and started from scratch.

I haven’t yet tried loading Performance Editor files created on the ES version into the Rack version.

I sent John an email yesterday telling him about this, and am awaiting his response.

Wow. This place is hopping. I’ve held the top 3 posts for a week now!  Mwahahaha!  The Forum Killer is here!  Oh, the humanity!

Anyway, John replied that it is indeed a bug due to the fact that the Rack ES has more User Voices than the ES8 (important thing to understand if your using a Rack ES to program for an ES).  ETA for a fix is likely June.

Meanwhile I’ll check out the XFactory tools.  I wonder if they offer full-featured editors like John’s?

If I was really a power-geek I’d be writing my own tools! Where’s that C book?  :)