Hi,
Please set your MIDI keyboard to send the values 0-127. Make sure the keyboard is not used as any Remote Device. Make sure there is no Input Transformer on the track. Add MIDI Insert > MIDI Monitor. Move the rotary knob.
What can you see in the MIDI Monitor now? I expect you should see continues data 0-127. If not, why is there the setup on your keyboard?
If it sends really just inc/dec values (I couldn’t imagine so), I did a patch to handle this in Max/MSP. It shouldn’t be a big deal to rebuild it with PureData.