The signal going to the shiftlights is individual for each light, so in theory it could be done. But it's a project that you would need to get some help with unless you are familiar with electronics. Thanks.
Is there any particular wire that sends a signal to the final shift light (the actual RPM to shift at) that could be tapped into?
If yes, which wire would that be?
I assume that voltage could be used to trigger a solenoid control for an air shifter, much the same way as other tachs send a signal to control electric or air shifters?
I don't know which wire it is. You would have to experiment. This is obviously not within the realm of product support that we can give you. Connect the volt-meter and see which output changes. Thanks.