Just throwing this out there.
I've not done any testing to specifically prove or disprove this.
I do use Joy Stick Gremlin which does use Vjoy and includes HID Guardian to HID devices from Windows.
I am using Joy Stick Gremlin to have different profiles for different games.
I am not doing any Axis Merging.
I started looking at Joy Stick Gremlin to see if would help me handle two Saitek
Throttle Quadrants in WOFF,
While they both show up in WOFF, they have the same name and thus cannot be configured separtely.
I was hoping to hide the Quadrants and combine them into a single Vjoy with Six Axis X, Y, Z, Rx, Ry, Rz.
I tried this many months ago and gave up.
As I recall, I came to the conclusion that CFS3/WOFF only likes the standard X, Y, Z axis.
As I said, take this with a grain of salt, my testing was not definitive.
Regarding the Sopwith Grip - It does not have any Axis - it has only buttons.
It attaches to a third party gimble which handles the Axis.
And WOFF does not even see the Sopwith Grip
The conclusion here is that WOFF/CFS3 will only see joysticks e.g. something with an Axis.
So Vjoy is used to create a device with at least one Axis and the required number of buttons that the Sopwith stick has.
And a Caveat, I have noticed some peculiarities went entering Claims in WOFF with JoyStick Gemlin active.
In order to Hid Devices, Joystick Gremlin must be started in Admin mode.
To Avoid getting off track I will not delve into this further here.