When I read the subject line and saw 'touch sensitivity' I assumed you meant aftertouch.
In my world velocity sensitivity is different than touch sensitivity.
And polyphonic aftertouch is even another 'touch'.

If you can get a less expensive controller and regain the keyboard action you lost at little cost, I'd do that first.
Tearing it apart, and risking doing more damage than good, seems avoidable at a low cost.

If you need aftertouch, though, prices go up pretty quick.

I do not work here, but the benefits are still awesome
Make your sound your own!