I've used the shift light function fine on my drag car.. but it did seem to be a bit hit & miss for working.
I'm going to give it another shot soon, but i'll be using it to trigger a relay that will run a shiftnoid on my turbo 400.
using a manual calibration tune.
but looking at the tune it's not supposed to be used for auto's.
Looks like my setup is completely different to what your trying to achieve.