Can a grounded metal mast ever be useful as a yagi reflector?
http://www.qsl.net/dk7zb/2m_veryshort/2ele.htm
apparently uses a metal mast as a sort of reflector.

If the mast is "very much longer" and "very much thicker" than the
other elements, does its distance from the other elements "stabilize"
in the design and not keep changing as we change the other factors.

Maybe this might be useful in making 'foolproof' 3rd world yagis,
where the user merely owns a tape measure and various metal rods. He
already has a reflector much thicker than the 50 ohm split dipole
driven element, so maybe thickness and metal type of the latter
wouldn't be that critical, as at least he could clip it to the right
size (=what?) for 144-146 MHz? Presto, he has a 2 element yagi?

Matters if he has stuck his mast right into the ground, so it is more
or less grounded or not?