Technical Support wrote:
An incident meter reading is what it is. The listed correction factor no longer matters. The factor would come into play if you knew the correct meter reading without the gel, then added the gel. You would factor the correction based on the un-gelled light.
I would suggest, however, testing your meter with gels. Meter white light, meter the gelled light, and see how close the gelled meter reading comes to the un-gelled meter reading and correction factor. test w a few gels across the spectrum (red, blue, green, etc).
Okay, thank you. No getting away from good old fashioned tinkering, I guess. ;)