Definitely HXEdit is at 3.1, and I definitely did the factory reset and restore for both units. And beyond that, I did additional subsequent backups to make sure I had good ones.
So I did a factory reset, then a restore of everything other than the presets. I then exported/imported the most resent preset I made on the Floor into the LT - this preset used the Floor-only feature of having a Command Center assignments to switches 1 & 7. When I brought it up on the LT everything looked fine, but when I pressed the MODE switch, the LT froze and had to be power cycled. So next time around, I edited the preset to remove those assignments, but the LT still hung.
I then did a factory reset to the LT, but instead of performing any kind of restore afterwards, I just imported that preset. No problems whatsoever.
I then did a restore from the same original backup, but ONLY restored the presets (no Globals, IRs, etc.). Restore completes successfully, and no problems with the new preset.
Factory reset again, this time I restored the Globals and Presets only. Restore completes successfully, but new preset hangs.
Factory reset again, this time I restored the Globals, IRs, and Presets only. Restore completes successfully, but new preset hangs.
Factory reset again, this time I restored the Globals, IRs, Favorites, and Presets only. Restore FAILs with -8609 error.
Factory reset again, this time I restored the Globals, IRs, User Model Defaults, and Presets only. Restore completes successfully, but new preset hangs.
I was able to reproduce this behavior on subsequent attempts.
Since it's relatively easy for me to rebuild my Globals by hand, I'm ok for now since my presets all restored and work fine if that's the ONLY thing I restore. I think it's appropriate to submit this as a normal bug report.