I don't know if the video is available online. I saw it on the engine owner's phone.
No one would ever see the bore slide out with an air shutoff on the turbo. You also cannot tell that the bore moves by just looking at the cover.
Yes it would be illegal because the air would no longer be traveling through the 3.0 bore.
"The turbocharger is smooth faced intake housing, limited to a 3.0” inlet, (no
map ring) with
all air entering through the 3.0” opening. Intake wheel must protrude 1/8th inch inside of opening."