Hi Dennis,
No. There is no direct file compatibility between MOX, MOXF, or Motif XS/XF Performances and the Montage. The fundamental difference between how Performances work in Montage prevents you from being able to simply open Performance data from the previous models.

As you may know, Performances contain links to as many as four Voice locations. Performances in the MOX, MOXF, Motif XS/XF store these Voices in Preset and User Voice locations... the Performance simply directs and applies offsets to the Voices via the Part parameters.

Say you have the Full Concert Grand VOICE, and you put it Part 1 of a Performance, but you apply the PART offsets so that it only plays C3 and above, and sounds one octave lower. In Part 2 you select an acoustic bass VOICE but again Part parameters define it to B2 and below. The Part parameters are like a window through which you access the Voice. The Voice must be in the target location... it is possible that the User Voice is not in the location, and your Performance is referencing by serendipity (your data is out of sync).

Say your acoustic bass Voice is in User 2, 004(A04)... if you were to Overwrite User 2, 004, your Performance would suddenly access whatever Voice happens to occupy that slot at the time.

This cannot happen on Montage.
First, there is no VOICE mode. So all references to where to find data is going to be meaningless.
There is enough memory now in Montage, that when you create a User Performance, Montage automatically recreates the entire program in the Part. No more applying offsets to an original Voice in another location. Montage memory for data is huge. Each time you use Full Concert Grand in a different Montage Performance, Montage creates a new uniquely editable version of the data. You are not referring back to a location, rather the data is copied and placed in its own location.

You will (should) never have an out-of-sync situation where a Performance is referencing the wrong sound.

That said, many (most actually) of the Arpeggio Library has been transferred forward- so you should find the same phrases. Montage ARP library is now 10,000. You can recreate Performances from previous models but it is very much programming from scratch.

I understand. There was a glimmer of hope, when I thought that the MOXF performances could be migrated. Thank you for your response.

I've migrated from MO6 performances to Montage manually. Since the MOXF is closer (in terms of generation) - the manual migration should be more straight forward. Hopefully we are not talking about a large number since it's time consuming. I just had one "important" one I migrated then started from "scratch" with the rest.

Mostly - how I organized the key ranges for different PARTs (previously voices) was most informative and I could replace with ballpark sounds copying over the old key ranges I used. There was only one performance with lots of tweaking and specific parameters I wanted to bring forward verbatim.