I take it you are running out of rpms at the 1/4 mile. The redline box will extend the rpm range, no question about that. The redline box will also get just about all the fuel that a VP44 can supply out of it.
It doesn't however take one of the computers out of the equation. The ECU still controls the advance and other parameters. The redline doesn't supply any additional advance. The redline box taps into two APPS wires, connects in series with the map sensor and two VP44 wires.
I don't run any faster with the redline box then I do with the edge drag comp. However it does run faster then using the TST comp on my truck, and is a lot more "friendly" when trying to build boost at the line.
What are you planning on stacking with it for timing?
Also try the 80-90% fuel settings on the redline. It maybe faster or as fast as 100%, because of depleting all the fuel from the rotor.
Oh, yeah... To answer your original question, it doesn't effect how my tranny shifts at all. The extra rpm doesn't help me, because the shift points are the same, and I don't hit the rev limiter in the 1/4 mile.
Hope this helps...
Paul