Naf, FWIW:

Thought that was something taught to all fledglings by a good instructor -
any time you'd be in deep yogurt if the mechanical pump failed and you
wouldn't have time to re-establish fuel flow before the ground comes up to
smite you.

If the mech. pump fails (on a normally aspirated engine), the engine will
continue to run until the carburetor is empty. If you turn on the "boost"
pump at the sound of silence, it will have to transfer some quantity of fuel
from the tank to fill the lines and float bowl before the engine will
restart. At low altitude (for me that's 2000 ft AGL and down), you may not
have enough time - at high altitude, that lack of noise up front is just a
large pucker factor until the engine fires.

For me, that means: the pump is definitely on for take-off and landing and
of course, if the engine driven pump fails at altitude.

I'd be surprised if any reasonable modern aircraft operating handbook
wouldn't include that as a key check-list item.

Dan Schaefer