Not sure if this an DAW or VST issue. Thought I would check to see if this was resolved in V2 but unfortunately not.
The midi map of the mixer joystick (pad x & y) appears in the configure section of the ableton VST device box and maps to my Korg Kontrol49 joystick which operates the pivot slider in the device window. This does not translate to movement of the joystick in the VST GUI.
Haven't tried mapping to my Origin joystick (which is far superior
) and will wait for v 1.1
However, it should be able to map to other midi controllers. Other mapping work OK eg osc tuning knobs