Agreed!<...>
As for "proof" ... sorry, dude, that's proprietary information.
Plenty of posts here from @davideduardo about the nuts and bolts of the testing process that our OP can go find and read. He's provided a wealth of info on that process over the years - how it was done in the early days as well as how it's being done recently.
What "proof" does our OP need? Well, isn't that what's on-air RIGHT NOW?! I mean, that song that just ended <<doesn't matter what it was>> had to have been tested for that audience on that station, which is why it's in the rotation.
🤦‍♂️