As far as I can tell, Kontakt only allows a min/max range of 12 semitones.
I see what you did with your script but I’m wondering why a script is necessary?
First of all, you can assign host automation values to the UP and DOWN Pitch Bend values in Kontakt so why could you not just use a couple of widgets mapped to those parameters and set them as needed?
And if that automation is not available, why not just have a knob widget learn the incoming pitchbend message, map that widget to the pitchbend message of the MIDI In block and then use a scaling curve?
For example, here I mapped a knob to the pitchbend wheel of my controller - obviously it goes all the way from 0 to 2^14 - 1
Then I set the scaling curve to cause that pitch range to be just 2 semitones below or above so pushing the pitchwheel fully to either end just changes the pitch in a Kontakt by +/- two semitones even if Kontakt is set to respond to pitchbend messages using the full octave amount.
