1) Yamaha is at a competitive disadvantage vs. other 16-part multimbral synths that support flexibility in configuring input MIDI channel number to each of the synth's "PART" equivalent.

2) Despite what you can and cannot do with Montage as it exists today, there are musically relevant reasons why this feature would be advantageous to the end user.

2.a) Compatibility with external hardware (legacy and latest production)
2.b) MIDI efficiency to avoid possible overflow (use of overlapping channels to avoid having to replicate messages for layering)
2.c) Routing flexibility: Allow more than one group of PARTs to be combined into a single channel such that multiple external controllers could target their own multi-PART instrument.
2.d) Other workflow possibilities members have contributed not mentioned above

I'm not sure those who mention they're fine with the system as-is are arguing against adding the feature - only that if it were added, they do not see using it given what demands they uniquely need out of the MIDI implementation. It's fair to present all sides to help understand the segment of the population Montage is currently aligned to.

+1 Thanks Jason

I hope Yamaha now understands it really does matter for a lot of users.

And I hope that Yamaha will fix this issue very very soon!

(I am waiting for almost two years now)