I think this is a manifestation of another similar frustration I've voiced before with the lack of digital input routing. Most of the ways out involve audio loop-back solutions so that you turn your digital input into an analog one - where there are more options for routing than afforded to by the digital input.

https://www.yamahasynth.com/ask-a-question/montage-usb-digital-input-as-modulation-source-for-vocoder

As a side-note: if MODX shares the same general architecture with respect to digital input and how it interacts (or does not) with Envelope Follower - I wonder how MODX would solve this problem as it does not have assignable outputs to loop back.

Very good point you make about MODX, I think too much focus/priority was given to the A/D input when developing the Montage, possibly because of the price point directed more to 'live' players and I remember the promotional material leaning toward the modulation signals coming from a live playing drummer etc, hence the implementation of tempo detection through the A/D input. Interestingly, a lot more live bands/artists are using DAW's on stage so I really think they have missed something. Sorry Jason btw, I tried searching for answers to my question and I only found this thread. I have just read your previous post on the subject and of course that would have given me the loopback workaround so thanks. It just goes to show, I am an engineer by day and I didn't think of that solution at all, possibly as a result of my mindset no longer considering solutions with older technologies, too busy looking toward the future innovations (which is entirely what Montage is about) and the development of USB has left me the legacy of a cupboard full of cables (fortunately so given this case). The workaround is acceptable for the time being. Unlike some Montage owners, I am happy about the MODX release as it shows Yamaha's commitment to the platform and gives me possibly naïve confidence that they will provide a solution to this. I also have Maschine Studio, which in principle is similar, a hardware controller but software at it's heart, Montage is essentially this but with the computer on board. I bought the original Maschine when it first came to market. It is a very different instrument today than it was then as a result of continued development of issues and feature requests. Given the firmware/software development of the Montage so far, hopefully this will continue to be the case and this issue is resolved.

Fingers crossed.

No problem, the last thing that link was about was to say you could've searched for the answer. It's difficult to search for things on a good day -- too much information floating around and not always the best tools provided to comb through it.

Rationale for providing the link was more to glue together related issues / wishes / complaints to help support how some intend on using the device. One outlier (or even a small minority) can be justifiably swept under the rug. If we're the only ones intending on using digital audio as a modulation source - then maybe it doesn't make sense to implement or think about additional internal routing capabilities in future products (or, if possible, in Montage).

The workaround isn't without its drawbacks and limitations - but it's one of those "trick up the sleeve" kind of things that can perhaps inch a setup closer to doing something not obviously supported.