To my knowledge, no one has gone to the dyno, done a run, swapped TB's, done another run, and then documented either increased HP or a change in where the power comes in.
That being said, I've actually seen people add cats, headers, and TB's to a car and lose power on the dyno.
If someone wants to loan me a set of TB's, I have a willing donor car (not mine) which is a ROE SC set-up w/ a built motor that we can run this test on. Back-to-back runs w/different TB's.
JD