It would be nice to have parity in outcomes between the two supported desktop environments (MacOS and Windows). Not necessarily the exact same everything (operating systems have differences you can't avoid) - but at least no loss of functionality from one supported platform to another. I'm not including mobile (which is currently only iOS) since I can understand that's a different world and there is no corollary to iOS as an alternative mobile platform.

There may be a reason for the difference - I know MacOS has enhanced capabilities like Aggregate Audio Devices allowing combining different audio drivers into one. Windows doesn't have this - and that's a difference. However, that doesn't entirely seem what's asked for here (doesn't depend on aggregate devices).

That said - within the bounds of schedule and resources (dev, testing, R&D, etc) - if feasible to offer some parity between the two supported desktop platforms - then parity in experience should be a goal. Not necessarily parity in how you accomplish the task in each environment. Having to add 3rd party "kludges" to get it to work should not be within the target solution set.

I'm not sure how difficult it is to implement as requested - there is a model for sending streams from the Windows System Sounds (including web pages) to Montage's Digital L/R as demonstrated by VoiceMeeter. It's technically feasible. Not sure how the work involved stacks up to other priorities in the chain.

There may be other ways to get this done as well. They seem more "expensive" (resource wise) - but I'm not particular. Such as being able to reassign, on Montage, the Channel-To-Input routing. For example: Montage Input Channel 1=Digital L, Montage Input Channel 2=Digital R, Montage Input Channel 3=Main L, Montage Input Channel 4=Main R, Montage Input Channel 5=Assign L, Montage Input Channel 6=Assign R

However Yamaha can bridge the current gap would be appreciated (if feasible - accounting for resource limitations, etc).

Use a mixer that makes up for lack of routing available by Montage's driver alone. Voicemeeter has been used with success.

That's not the only way, but one which has least compromises overall.

Request to add this function to Yamaha Steinberg USB drivers was made - but that may never happen.

I didn't hear any feedback using the settings in the picture of this post https://www.yamahasynth.com/forum/use-montage-cubase-to-record-from-internet#reply-31049

We all have different sound cards and features. That's the "fun" of the PC experience - no two manufacturers or models are identical (unlike Apple which has more of a "lock-down" on the hardware experience). Therefore, I cannot make any real inferences about your setup. You have to supply lots of info.

Echo is usually there because you have a microphone turned on that should not be. Be sure all audio sources that are microphones are turned off. My setup has no microphones turned on - so I hear no feedback. If you need a microphone turned on - then you're going to hear feedback when the speaker output gets recorded into the signal and then comes back out the speakers - just like any other type of feedback. If recording with a mic - the best way to control this would be to use earphones to isolate your audio output to a very small near-field that is not picked up by the mic.

There is no user-serviceable front-door way using the Yamaha Steinberg USB drivers as the soundcard (Windows 10 Audio Mixer default sound output) driver to direct audio to Montage's Digital L/R inputs

I find this shocking, because this is a very simple thing to do when running the Yamaha Steinberg Firewire driver with a Motif XS/XF. That driver supports routing Windows system audio (WDM, non-ASIO) to any of Main L&R, Digital In, or Assignable Output. This is usable even while software like Cubase is simultaneously using the ASIO driver in exclusive mode. It's also possible to route any of the Motif digital outputs to Windows system input.

It's unfortunate that the newest Yamaha Steinberg audio driver is apparently now less capable, 10 years later.

mLAN/FW is an entirely different Driver, entirely different.

Might be something worth opening in ideascale - more flexible system audio routing using the Yamaha Steinberg USB driver.

This could be the solution for your problems

Might be something worth opening in ideascale - more flexible system audio routing using the Yamaha Steinberg USB driver.

I went ahead and created the Idea.