fwiw, I'm a fairly high time pilot (IFR). I need carb heat a lot more
than pitot heat in VFR. At run up on a normally carburated engine if
you don't get an RPM dropoff when you pull the carb heat on, you don't
go. There's no such test for pitot heat (although I will tell you if
I'm going IFR I turn it on for a while when first in the cockpit, then
make sure it's warm during the walk around.