I found the docs to ST2.5 and it is very easy to set the volume to CC11.
-------------------------------------------------------------
This is straight from the docs:

3 - Controlling SampleTank 2

Click-on-the-MIDI-CTL-button-(figure-.45).
Click-on-any-of-the-knobs-you-want-to-automate-(figure-.46).
The-MIDI-CTL-Association-window-will-be-displayed.-This-window-contains-four-columns:-Knob-(that-include-the-name-of-the-knob-parameter),-the-Min-and-Max-values,-and-the-Controller-Number-(that-contains-the-controller-number-associated-to-that-particular-parameter-or-shows-N/A-when-no-controller-#-is-assigned-yet),-(figure-.47)
.Click-and-drag-on-the-Controller-Number-field-to-associate-a-MIDI-controller-number-to-the-parameter-that-you-want-to-control-(figure-.48).
To-disassociate-a-MIDI-CTL-from-a-knob,-simply-select-the-N/A(not-available)-value
-------------------------------------------------------------------

In simpler terms select a sound and put it is ST2.5.
Click on the MIDI-CTL button
Click on volume for the instrument you want to control with CC11
In the pop up window that appears left click and hold on the volume controller number and move the mouse up or down to increase or decrease the CC number. In your case move your mouse until CC11 shows, then stop.
Click ok and your done, now your volume is controlled by CC11
-----------------------------------------------------------------------

As you have read using CC7 for volume changes is a nightmare if you have to change volumes during the mix. With CC11 to change the overall volume you would just adjust CC7 and CC11 will follow along with your relative changes.

I hope this helps.

The fitness trainer asked me, "What kind of a squat are you accustomed to doing?" I said, "Diddly."


64 bit Win 11 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware