Hmm, what about simply change the texture of the instrument, to make it work linear. I know that isn't realistic, cause some instruments in the KA-50 aren't linear, but if it's possible to adjust the texture to a linear one, it could be a workarround until we know more about the code that stands behind it.
If we are able to make it the right way, it's no big deal to change the textures again. Don't know if it is even possible, because of the scaling needed to show the whole indicating range, but if, this could be a solution for now, for sure not for ever. Better a working instrument than nothing