Thank you so much for the information. While I understand the dynamic curve changes with the processing time, I was trying to find out what's the objective measure for push processed slide films? Although Fujihunt chemicals come with recommended processing parameters, I've found that they are merely starting point, and they needed to be tuned for each processor. For example, the recommended First Developer time for normal processing is 6:00, but I've found that using the Phototherm SSK-8r, it is necessary to run it for 6:30 - otherwise film speeds will tend to be on the low side. Likewise, going with the official recommendation for push processing, it will result in films that look under developed.
I figure that there must be an official standard for E6 film speed, something that I can establish with the control strips. If anyone knows of such documentation, I would really appreciate the pointers.