QTR-Quadtone RIP

Maybe some of the advanced users of QTR can shed some light regarding linearization.  
Currently printing on a 7600/UC/Windows.  

After building the initial separations for L and LK, I read the patches and notice that 
eventhough there is a gradual change in each patch from paper white to ink black, I do have 
a bit of a flat spot in the three quarter tones and not enough separation between 95% black 
and 100%.  I load the measurements into the Linearization tab and create a new curve.  I now 
print a new 21-step wedge and notice that the steps are more evenly spaced, no flat spots 
and separation between 95% and 100%.  All looks good.  

The question I hope to get answered is:  What is QTR Linearization or What is QTR Linearizing 
to?  Does the program just create even steps between paper white to DMAX?  Or does it 
Linearize to a specific Gamma like 2.2?  If I'm editing in a Gray Gamma 2.2 space, should I try 
to create a QTR ramp that matches the same ramp as Gray Gamma 2.2?

Hope some experts can shed some light.  I just want to understand this linearization process 
a bit more clearly.