Currently, no you cannot merge these two libraries. Good news though: We will rectify the situation by posting both .X7L and .X7U versions of the data.

Here's what is happening:
The Library File can only be installed to a Library location. And the Library Import function does not COPY the User Curves or Motion Sequences to the USER Folders (which is necessary for you to move them into a new Library).

The author would have to provide you with their original USER data (in a .X7U file) so you can decide what you want to do. The USER File (.X7U) could be loaded directly to the USER Bank which would place the 19 Performances, 18 Curves and 23 Motion Sequences in your USER Bank folders...

A Library File can only be created from a MONTAGE's User Bank. I'll see if I can get them to post both the .X7L and the .X7U version of the data. This way you can decide what data you want to do with the data.

Thanks for raising the question... Hopefully, we can get the additional version posted shortly.

Thank you Phil.
Library Curves or Library Motion Sequences cannot be "import" with performances from Library import function to user area but Library arp from are "import" with Library performance if i understand fine ?

@ Bad Mister

Thank you for your advice.

@Joel
As I know:

When importing a performance all waveforms and arpeggios used by this performance are import in memory user.

Motion Sequences have not to be imported because motion sequence are in the performance itself, (same way as a part add in a performance).

Only curves are not imported (perhaps a bug).

When importing several performances there are no duplicates for wavs or arps.

But individual import make duplicates.

Waveforms and arpeggios that are not referenced by performances imported but are inside the lib are not copied in memory user by import procedure.

For those who would be interested, after retesting all:

Importing performance copy waveforms and arpeggios referenced by the performance in user memory.
But curves and micro-tuning referenced by the performance are not copy in user memory.
So, i think it is not useful to import these type of performances.

For those who have forgotten to save a .X7U with the .X7L, you can rename your .X7L to .X7U and load it in user memory to retrieve your datas.
This is only a workaround and not an advice because the format of .X7U and .X7L can differ in future os version.

Reminder:
Performance dependencies can be waveforms, arpeggios, curves and micro-tuning.
Dependencies mean that there are pointers to that datas inside the performance instead of data itself.
So for instance motion-sequence and part are not dependencies because there are no pointers in the performance but the datas instead (see datalist).

(You can use my soft to see what's in X7 files and to see the dependencies of performances in user or lib memory)

Thank you Jean 😉

Yamaha, please update the Montage to include user curves when importing libraries.