I prefer 1:1 even on a street car and here is why..........FIRST, this is not a carb. Progressive linkage on a carb, is usually to keep the car from stumbling when you snap all that air blade open and the carb can't deliver the fuel fast enough. That won't happen with EFI. If I have 4 blades, I want them all working in unison to provide an equal flow of air to the plenum. The rest is just in the tune.

Remember, the throttle body is just strictly an air valve. It does NOTHING else. I want the flow even through it, not half of it, until I decide to stand on it.