Green screen, set Kelvin (WB), so green matches vector scope

Hello there,

I am looking for a second opinion:

A local guy, who has his own professional green screen studio, advised me to adjust my Kelvin (WB) in the camera, so that the green from my green screen matches the color bar green. In other words it matches the green in the green spot on the vector scope. He said that it makes the keying much more reliable. After the keying the character has to be color corrected back to its original state.

The following pictures show:
-1x - the kelvin (WB) matched in the camera, so that the green hits the vector scope green
-1x - the Kelvin (WB) set in the camera with the use of a white balance card (so a proper WB)

Kelvin-to-match-color-bar-Green.gif (324.72 KiB) Viewed 819 times

Kelvin-WB-made-By-camera.gif (285.59 KiB) Viewed 819 times

My question is:
-is this a good idea or not? cause at the moment i can't see the advantage of it, cause i tried keying both and i can't find an advantage keying the footage with the Kelvin (WB) set, so that the green hits the green spot in the vector scope.

I hope somebody can explain me why to do it? Or why not to do it?

Thanx in front
Greetz Lenny