Montage OS 3.5 came out recently and introduces the Smart Morph feature for the FM-X engine, as well as a number of other features including:
Add parts during record
Realtime overdub controller data
Improved erase event job
Improved get phrase job
Improved normalize play FX
New pattern chain play
Undo/redo on any page
Jim takes a look at Smart Morph for us - as a long time Montage owner, he appreciates that the instrument is still being updated, adding new features. the Montage OS 3.5 is free - though Yamaha (us too!) recommend backing up your data before performing the upgrade.
You will need a 1GB USB flash drive formatted on the Montage.