I'd be glad to try to shed some light, but I'm not sure what the subject is here :-). Can you provide some more details about what you're trying to do? In particular, what do you mean by "interpret the data", and "doesn't work"?
I'm using the BCF2000 with SX 3.0.2, Stylus RMX & K2.
Works great with Stylus-RMX.
[ I'm using the BCF in USB mode]
SX-3: Go to the <Devices> Menu at the top of SX3.
At the bottom of this drop-down you'll see Device Set-up
I got this from the SX-Manual:
In MIDI, All Midi Inputs, I've checked the BCF (USB Audio Device) as No in Active. (So it's not active)
but Active in 'Windows Midi'.
That's the hard part over.
Then for stylus:
In SX I've got the individual Midi channels to accept midi data from the main piano type controller.
Then I've got another channel set up to control Stylus RMX in 'ANY'.
The In is the USB Audio Device (BCF).
Then it's as simple as:
Stylus: Midi Learn.
Toggle the dial you wish to automate.
Move the slider on the BCF.