SD 240V Controller Pot: 50%=0, too sensitive

[pickled]

I have a SD 240V controller with a 6500W element. I've found that the controller will send no power to the element until the potentiometer knob is rotated to about 45%. From this point, the controller will start sending ~800W through the element. The control is extremely sensitive up to about 3500W.
Is there a way to reduce sensitivity and have the pot output be more linear? ie. 10% knob = 10% power, 80% knob = 80% power
I'd like to avoid adding another potentiometer because my box is a little crowded.

I read mention in another thread about putting some kind of resistor in parallel...