I wondere how much of a temperature gradient might be present in the
fuel/air stream at the sense point of a carb air temp gage. A lot of
things are happening quickly as air comes thru the air intake (heat off
only) or heat system, and then on to the carb heat box valve system
before it goes into the carb venturi, where the air is expanded & the
fuel added.

I agree that it is better to have an air temp gage but maybe one should
be a little suspicious of it.