QUOTE
"Or have the sub oscillator go from 0-50 in volume (full on at 50) and at 51-100 change to noise so you don't loose the sine sub-oscillator"
I had the same idea, but with silence in the middle position (50) and the sub oscillator to the left full on at 0 and the noise to the right full on at 100.
But I guess changing the existing basic waves is not an option, because of backwards compatibility. A new oscillator typ "Basic Waves / Noise" wouldn't mess this up.