After much hair pulling I finally got the above formulas to work. Here's another explanation.

To make swing work: This example is set at tempo = 152
Create a measure with 8 eighth rests in it.
Insert multipoint controllers(MPC)before each eighth rest.
choose controller: Tempo; style : Absolute; time resolution: Quarter; sweep resolution: 1

For 1st eighth rest set initial setting, time offset to 0
then set control slider to 114 (which is 3/4 of the desired tempo, in this case MM = 152)

For the 2nd eighth rest set the initial setting, time offset to 0,
then set the control slider to 228 (which is 1.5 times the desired tempo, in this case MM = 152)

Alternate these two MPCs for each eighth rest in the measure. There will be a total of 8 MPCs, 4 of each description alternating between the two.

What NWC is actually doing is slowing the tempo down to 3/4 of the desired tempo for the first eighth, and then speeding it up to 1.5 times the desired tempo to compensate for the slower tempo of the first eighth.

In the example given, NWC will produce a swing feel of 2/3 +1/3. This method will work for any desired swing feel. See the above tips for additional formulas.

Once you create the above swing track, you can use it as a control in all of your jazz scores. Save it as a template and you will only need to change the MPC slider values according to the desired tempo. It only needs to be one measure long since you can use the local repeat feature to specify how many measures for NWC to play it. Repeat it for the same number of measures as your arrangement and NWC will swing your music from beginning to end. I place it at the bottom of the score and hide it from view.