Quick answer: yes and no. Probably not how you would like ...

The journey (more detail):

On a random performance, I spun the superknob and see:

00004DD7 1 -- F0 Buffer: 11 Bytes System Exclusive
SYSX: F0 43 10 7F 1C 02 30 4B 00 04 F7
00004DE1 1 -- F0 Buffer: 11 Bytes System Exclusive
SYSX: F0 43 10 7F 1C 02 30 4B 00 02 F7
00004DEB 1 -- F0 Buffer: 11 Bytes System Exclusive
SYSX: F0 43 10 7F 1C 02 30 4B 00 00 F7

Duplicating more of your setup, I'll change the destination and see what happens.

I already had common assignable knob 2 assigned to many destinations, so I deleted all of them.
Common assignable knob 1, I left as-is (part 5, assignable knob 1 as the destination).

In Part 5, Assignable knob 1 - the destination was cutoff. So I changed that to Part Volume instead.

I still see the SysEx

00004DD9 1 -- F0 Buffer: 11 Bytes System Exclusive
SYSX: F0 43 10 7F 1C 02 30 4B 00 39 F7

The 2nd to last value (39 above, and 00, 02, 04 going further up the email) is the superknob position.

I think the way that superknob works that its destination is always affecting an offset to internal settings and this offset is an internal construct. Therefore, superknob doesn't use standard MIDI to control parameters because this would affect the "true" setting vs. the offset value.

You'll notice from the data list that "30 4B 00" (montage_en_dl_v110_b0.pdf page 189) is "Super Knob Value". So, for me, all that happens when I spin superknob is the SysEx data for the Super Knob position itself is communicated via MIDI. The destination-type information is not conveyed.

Maybe there's a "trick" - but I do not readily see a way to get there.

The best control for volume I see is to press:

1) [PART CONTROL]
2) Number A [1] (just select any part 1-8) - optional if green LED to left of faders does not already show "PART 1-8" after pressing button in step 1
3) Use fader 7 to control part 7 volume.

Doing so, I get:

TIMESTAMP IN PORT STATUS DATA1 DATA2 CHAN NOTE EVENT

000EBCDF 1 -- B6 07 6B 7 --- CC: Volume
000EBCF8 1 -- B6 07 6A 7 --- CC: Volume

Which the "7" is MIDI channel - not to be confused with "07".

How can I control an external device with the super knob or a general (common) assignable knob?

In my setup, part 7 controls a Korg synth. In this part 7, the assignable knobs control this external device (knob 5 sends #21 which controls the volume). I can control the assignable knob of part 7 with a general (common) assignable knob (f.e. knob 1) cq the super knob.

Although common knob 1 is controlling knob 5 of part 7, no data is being sent to the Korg synth. How can i control the Korg synth with the super knob or a common assignable knob?

When you setup a PART to control an external device, (you do so by activating the Zone Master function in the Part), you can pre-set a volume, a pan position, send an MSB/LSB Bank Select and Program Change to an external device. The Part (Zone) has eight Assign Knobs 1-8 which default to send cc17-24, respectively, Out via MIDI, when you Select (highlight) that Part, and [ASSIGN] is lit.

How or even if your external device will be controlled by the Super Knob will depend on what cc you have it sending... The Super Knob can be set be set globally to send CC: OFF, 1-95; when Off it sends Sysex. When set to a cc number, that number is sent Out via MIDI.

The Super Knob rules over the internal domain of Montage at all times, whether [ASSIGN] is lit or not. It does not matter what you set it to send Out via MIDI, it continues in its unique relationship with the internal tone engine, at all times.

External devices can only be controlled by physical controls directly (they are not part of the internal Controller Set matrix of Montage). The Super Knob, also being a physical control, can be set to send any cc number 1-95. If you set it to cc1 it will become the MW Out via MIDI; if you set it to cc10 it becomes a Pan control Out via MIDI, etc.
you will see an "!" IF it supersedes another knob assignment. That is if you set it to the same value as one of your Assign Knobs.

The AssignKnobs can send any cc number 1-95

Changing what these knob send, in terms of cc number is only significant OUT via MIDI. They will continue to address the internal Montage parameter as programmed in the Montage Part, exactly as assigned, regardless of the cc number the generate. CC number is only recognized from the AssignKnobs and Super Knob by external devices, Out via MIDI.

When your external Part is selected (highlighted), directly, moving the 8 knobs available for your external synth will control the external device. The LEDs do not represent your external device, they will represent what is currently being sent to the internal Montage. (they are after all Montage lights)

If Part 7 is setup as an external Zone, press [PART SELECT 7]
With the [ASSIGN] button lit, the knobs 1-8 send Out via MIDI
Default is cc17-24

The Super Knob assignment is a global setting (MIDI Settings)
The 8 Assign Knobs assignment is set on a per Performance basis. (Common edit)