(Steve Firth) gurgled happily, sounding much like
they were saying:

Err, no. Air "mass" meters are horrid things, and you don't want one
in the airflow when tuning for maximum power.

Perhaps you're thinking about the old flap valve type? Modern ones very
little if any resistance to airflow.

The air mass meter on my car has about half the cross-sectional area of
the air filter or the manifold. I'd say that was offering fairly serious
resistance to airflow. Fortunately third party tuners sell properly
sized AMMs.

....which just shows it's not an inherent issue with the concept of the
AMM...