My question : Is there a way to do this globally so all factory and user patches will use the Expression Pedal to control rotary speed?

No. An FC7 set to do Expression (cc11) will always, by definition be an Expression Pedal. We know what you mean... you want to use the FC7 pedal plugged into the Foot Controller 1 jack to send CC1, globally,... still the answer is No.

It is as you stated, on a per Performance basis.

What you can do
We assume you are more comfortable switching the Rotary Speaker “Speed Control” with your feet.
Press [UTILITY] > touch “Settings” > “MIDI I/O” > set the FS ASSIGN = 1

Now a Foot Switch plugged into the Assignable Foot Switch jack will act as a surrogate MW.
If you use a momentary FS — You will need to keep your foot on the pedal (works like a sustain) to keep the speed change.
If you use a clickable FS — You can tap it once to cause the Speed Transition to begin... you do not have to keep your foot on it to maintain the speed change

The FS ASSIGN is global.

Ok thanks Bad Mister. The foot switch method does work and I think solves my problem. I appreciate the help.

One thing I'm curious about -- I previously assumed that I needed a variable controller (eg Expression pedal) to emulate the function of the Mod Wheel using a pedal. With the MODX factory organ patches is the rotary speed continuously adjustable using the Mod wheel or is the programmed behavior just to speed up the rotary (with some 'inertia') once a certain threshold is passed with the mod wheel?

With the MODX factory organ patches is the rotary speed continuously adjustable using the Mod wheel or is the programmed behavior just to speed up the rotary (with some 'inertia') once a certain threshold is passed with the mod wheel?

The Rotary Speaker “Speed Control” is a Switch. One direction is SLOW (called “Chorale“ on the Leslie) and the other direction is FAST (called “Tremolo).

The change is a switch - either/or - the MW most closely mimics the actual Leslie switch... shown below

On a well tuned Leslie the change was almost instantaneous... but as the system got worn the physical belt would loosen and slip, and the "Transition Time" parameter was born. On the actual Leslie it was a fault of worn equipment... On any simulator it is manufactured to emulate the physical fault.

Back in the 1950s and 1960s, when the "Speed Control" half-moon rocker switch was flipped, it was virtually instantaneous Speed Change - any thing less was a trip to the repair shop... the "Transition Time" (loose belt thing) started to creep into the vernacular in the psychedelic 1970s, it became “hip” to have a loose belt Leslie. (Bell bottoms and mutton chop sideburns were in, too).

So every simulator, including those here, have a programmable Transition Time parameter set... it lets you set the Slow Speed for the Rotor, the Fast Speed for the Rotor, and the amount of time it takes to transition between these two setting. Separately, the same thing for the high frequency Horn (a Slow speed, a Fast speed, and a transition time setting). But the Speed Control is a Switch. SLOW/FAST. The Transition Time is programmable.

Extra Credit:
One difference the MW does allow is you can determine where in the wheel’s travel the *switch* is flipped. As you know, the MW Sends values 0-127. If you use a linear Curve all values 0 thru 63 = SLOW, and all values 64-127 = Fast. By adjusting the Curve Type and Param1 (shape) you can move *where* in its movement the switch occurs.

A FS, of course, is 0 in one position and 127 in the other. But the advantage is, you can work it with your feet.

To learn more about programming the Rotary Speaker detail, please see this article:

Link: Rotary Speaker Effect
__ Although this is for the Motif XF, the parameters are the same and it will apply...to both MONTAGE and MODX Rotary Speaker parameters.

To learn about programming the Rotary Speaker within the MODX Control Sets please see the following Tutorial Article

Link: Mastering MODX: Controller Box Switches

I was using a momentary to control the Leslie but it got old so I went back to mod wheel.
But I like the idea of a clickable switch. I'm going to look for one.

Plus, I also like the idea of having 4 pedals on the floor. Makes me look cool like a guitar player. 😀

Awesome!

I had an existing ideascale item to allow to program the footswitch as a latching switch (without requiring purchase of a latching switch) - but the idea also included more ideas on how the footswitch can be enhanced outside of only momentary vs. latched. I added a new one that only focuses on allowing the footswitch to assume momentary vs. latched if assigned to the same CC as an assignable switch. That, when the footswitch matches an assignable switch, the footswitch would assume the assignable switch's setting for latched vs. momentary. This allows for Performance-to-Performance choices in a footswitch as latched as a controller source.

Yes, it would be nice to be able to allow FS1 to be programmed as Momentary or Latched.
I built my own custom latching pedal and mounted it next to my Sustain pedal (sostenuto pedal).
The custom pedal is a bit clunky but it works for my needs.

Ideally, it would be great if the Sustain pedal were assignable to allow the Leslie effect to be latched on and off when playing organs.
I suppose this could be a setting at the Performance level rather than the Global level so that the sustain pedal could be used as its intended for Pianos sounds and such.
One less pedal to carry around, plugin and eventually break...wishful thinking....

In some keyboards sustain is not tied down to the sustain function. This makes a lot of sense when you are emulating one or an array of instruments that do not have or need the sustain function. The ability to reassign the sustain pedal would be welcome. Latched or momentary or even as an expression pedal when using a continuous/half-damper sustain pedal. Certainly per Performance.

Or even per Part. If you did have a piano - you may want it set to use the sustain pedal as sustain and other Parts to ignore sustain but use sustain as a source controller (continuous sustain) and use the value of the pedal as a way to "duck" a pad. One possible usage. That may be too far left field (too many buttons in the cockpit).