Hmmm, just be make things clear (I hope)...

Can you explain what your background is on this subject? I haven't
seen your name before.

The vector...originates in...the IFR facility (radar approach
control or center) and is *relayed* to the aircraft by the tower.

Nah, that doesn't work for me. The radar facility doesn't have you on
radar either, because you haven't left the ground, so they can't
vector you either.

Again, the most significant way in which this heading differs from a
vector is the lack of obstacle protection. If I have to climb 10,000
feet before radar can see me, who is providing obstacle protection?