The Montage has these two Performances:

Classic 80's DX7 EP
The FM DX7 Organ

Michael, Montage has a full FM engine, with tons of sounds, and full compatibility with all DX7 sounds. All that's missing is the breath controller input. (MODX is similar, though also missing the aftertouch, and having a lesser quality feel overall.)

Personally, I have doubts that there is a big market for what the OP describes, which sounds like basically a Montage with the AWM2 engine removed.

Given how hard FM-X is to program, and the power and integration of motion and the effects unity in Montage/MODX, it'd have to include these.

In which case, the ideal is probably an 8 note polyphony little equivalent of the Korg NTS-1, with browser based editing facilities for all the layouts of motion, effects and algorithms.

Click here for Link to Korg NTS-1

This way the price could be brought down to where hobbyists with the required skillsets could go nuts with these things and perhaps program animated control of the superknob in the browser editor in a way that the patches can then be brought back into the Montage and MODX.

And the device could be used as an outboard effects unit, with 8 voices of FM-X for the rest of the world. So perhaps it should be in a pedal box.

And the device could be used as an outboard effects unit, with 8 voices of FM-X for the rest of the world. So perhaps it should be in a pedal box.

This sounds like something belonging in the Reface product line, not the flagships.

Probably the bits left out from the original DX7 in terms of features would be desirable. Glissando and various other omissions.

Personally, I have doubts that there is a big market for what the OP describes, which sounds like basically a Montage with the AWM2 engine removed.

Korg seem to think there's a market for this sort of thing with their OPSIX.

It would be great for Yamaha to introduce the Excellent FM-X engine to those with slightly shallower pockets. I'm having a blast with it.

the ideal is probably an 8 note polyphony little equivalent of the Korg NTS-1

That's very different from the OP's request for something with "the same quality key action/build" as a Montage. Closer to an updated Reface DX.

Korg seem to think there's a market for this sort of thing with their OPSIX.

Again, that's more in the "updated Reface DX" category. If you're looking for a Montage 6 calibre 61-key action, metal chassis, internal power supply, and all the other things Montage brings to the FM experience like extensive effects, motion control, and touchscreen interface, you're not talking about an OPSIX kind of price or travel weight. Maybe I'm misunderstanding what you really want...?

Korg seem to think there's a market for this sort of thing with their OPSIX.

OPSIX looks nice but if I get into that price level, I'd rather put a bit more money down and just get a MODX6.
Or to put it differently, I'd rather ask for a 49 key (or even 37 key like the opsix) MODX for just a bit more than opsix.
Or, a MODX as a desktop module for less than the opsix. I'd certainly buy that and use it with my Studiologic weighted keyboard, aftertouch and all 😀

Part and parcel of the appeal of the DX-7, for a huge swathe of time, was the enormous number of readily available custom presets. This is what Yamaha needs encourage the creation of to increase the viability and attractiveness of the FM-X engine.

SoundMondo is pretty much a failure in this endeavour, as it's got no decent sorting, no decent searching, no decent classification systems, primitive tagging, zero previewing when not connected to a device, fails to provide any significant kudos for designers, is horribly designed and very poorly implemented, and doesn't provide any means to dissect and understand patches, nor to preview them even with playback of recorded waves or SoundCloud examples etc.

SoundMondo is a bit of a sad joke, long before it's compared to decent integrations like Roland's ZenCore and Korg's logue SDK works.

If you don't understand what Korg has done with the Prologue, Minilogue, NTS-1 and logue SDK, then it might look like any smaller suggestion is Reface nonsense and guff.

It's not. The NTS-1 is a genius level outreach to capable programmers and hobbyists at an inspired pricing, and is massively furthering the appeal and marketability of the Prologue and Minilogue by virtue of the content being created for the "baby" of the family.

Granted, the FM-X engine is a bit more complex than the base setup of the logue SDK's physical realisation in the NTS-1, but there's no need for a programming and SDK support, just the cheapest possible access to the main ingredients of FM-X.

FM-X Main Ingredients:

The FM-X engine is a combination of 3 key elements. FM with 8 operators, Effects at Voice and Main stages and the integration of these with the dynamically animation abilities of Motion Control.

Even if only mono-timbral with 8 voices, this is still the marquee FM-X 'engine', and a huge and incredible system, that could/should be packaged for the cheapest possible access to this programming toolbox for animatable FM sound creation.

Given two huge factors: world economic collapse of live music revenues for performers and their being at home combined with a need to utilise the more programming centric thinkers of the world to get great results from such a complex sound engine, making it as cheap as physically possible opens up access to everyone to craft, curate and shape the creation of amazing performance parts.

Having done that, putting FM-X in ANYTHING then makes it more attractive, by virtue of a huge array of sounds and motion based sounds having been created with it, and this also increases the longevity of all products using the FM-X engine.

Because this hasn't yet happened with anywhere near the pedigree and impressiveness of DX-7 programming during its key years, FM-X as realised in the Montage and MODX is in danger of becoming a unicorn.

Totally agreed.

I suppose what I'm asking for is a way of "democratising" FM-X by putting it in something relatively less expensive.

Yes the MODX is much cheaper than the Montage but it's way less expressive with an inferior keybed, no aftertouch, no ribbon strip and less controls.

FM NEEDS modulation options to come alive. To me MPE or at least polyphonic aftertouch would bring it alive in whole new ways.

Sorry to sound evangelistic but I love FM in general and FM-X in particular.

I suppose what I'm asking for is a way of "democratising" FM-X by putting it in something relatively less expensive.

Yes the MODX is much cheaper than the Montage but it's way less expressive with an inferior keybed, no aftertouch, no ribbon strip and less controls.

FM NEEDS modulation options to come alive. To me MPE or at least polyphonic aftertouch would bring it alive in whole new ways.

If you take out the AWM2 engine and it's associated factory and user sample memory but put in a polyphonic aftertouch (or better) action instead I'm not sure how much less expensive it gets. I suppose cutting the effects and FM polyphony and numer of front panel controls down to MODX level would help... What else are you willing to lose?

Well, that's one of the reasons I said "MODX as a desktop unit", probably best implemented as an audio interface with the MODX engines inside.
And with a nice software interface for it.

Agree with anything that's more "hacker friendly".

I've wished for more community-enablement of providing 3rd party support for Yamaha synths.

https://yamahasynth.ideascale.com/a/dtd/Value-Open-Source-Design/210042-45978

I even reference Korg's SDK as an example of what I would like to see as a growing industry trend.

Yamaha keeps their cards close to the vest - so this isn't something that seems plausible given the culture and history of Yamaha. Even trying to go through official channels that have been suggested to me - finding programming information has been a dead-end. I'm not against discovering it on my own and am capable. It's just somewhat of a waste of time to invest if there's documentation that can curtail having to spend countless hours injecting stimulus to read the outcomes and documenting the system that way.

However, I feel that Yamaha has more to gain than lose by fostering an eco-system of 3rd party tools (editors, converters, widgets, whatnots) contributed by the community.

Great idea!
One other thing, somehow similar, would be to embed a lightweight scripting language.
Would be a natural extension of what they're doing with Motion Control already.
Virtual synth workstations like UVI Falcon or HALion have Lua, which offers great options for those willing to dig in.
And Lua, which is light and made for use in embedded systems, would be great option for something like the Montage/MODX as well.