The simple answer is 'no'.

By default you can plug FC7 into footswitch 1 and it will control the volume of all parts that have keyboard control set to ON.

But it won't affect the volume of parts with keyboard control OFF unless you first select the part - in which case that is the ONLY part it affects the volume of.

And it can only affect 'volume control' within the limits set by the performance and by each of the parts in the performance.

The pedal has a range of 0-127. But the value of 127 (toe down) represents the performance level setting. If a performance has a level of 20 then the pedal range (heel down to toe down) will be 0-20.

And there are volume/level settings at the performance, part and element/operator levels.

The performance level restricts the range that the part level represents and each part level restricts the range than its element/operator represents.

performance -> 0 - 127

part             -> 0 - 127

element/op  -> 0 - 127

If perf value is 63 (1/2 the MAX) then the effective range is 0-63. So a part value range is now 0-63 meaning 127 represents 63.

A part value 63 (1/2 the MAX) restricts the element/op range so an element/op value of 127 is now really a part value of 63 which is a performance value of 31.

So for the footswitch to be able to control the whole range from 0-127 the performance level needs to be 127. Not all of the presets have a level of 127. 

Do you have a specific use case in mind?

Excellent, you nailed it, and some!   Thank you!

I am using scenes within my performances so I have keyboard control turned on for the parts I need volume control, so I am good.  I appreciate you going beyond the extra mile too explaining how the volume limits within parts impact overall volume control as well.

Proportional versus absolute volume/level changes.

Front Panel master volume knob also affects the level for all performances but it changes the level on an absolute basis and NOT proportionally. The position of the master knob limits the highest level any performance can reach. So at MIN you won't hear anything even with the performance set to 127.

The performance/part/element hierarchy mentioned earlier makes 'proportional' changes. Changes at the performance level keep the parts in the same proportion to each other. Similarly, changes at a part level keep the element/operator levels in the same proportion to each other.

So if the performance level is set to 40 the part setting (0-127) gets mapped to a range of 0-40. That is, a part setting of 127 really represents 40. Part levels between 0-127 get scaled accordingly.

Hope that makes sense. And don't forget that equalizer settings, and control assign curves will affect volume/level also.

RE Scenes - often forgotten is that a new scene will INHERIT the current settings unless the new scene has its memory enabled to remember a different value. So if you change a parameter (knob, slider, pedal) while in scene 2 and then switch to scene 3 the parameter you changed will still have that new value.

A new scene will ONLY change the values of parameters it has memorized.

If you change PAN in scene 2 and then switch to scene 3 then scene 3 will also have that new PAN value unless you have modified scene 3 to memorize a different pan.

So if you already have established scenes and later decide to change a scene to memorize a new parameter you need to make sure you modify ALL of the other scenes if you need them to use the old value.