Even if it did "work" what benefit would it be?

Varying the fuel pressure to the carb is going to ruin the tune of the engine, theoretically the only way it *could* work is if the carb was heavily modified so that the only factor regulating fuel flow to the engine was this regualtor...the needles would have to be removed. And how is exhaust temperature directly linked to fuel supply anyway? Temperature is the result of MANY different factors.

It's just a gimmic, and not a very convincing one at that.