Rainboe,
Is your "g meter" just a thought experiment, or does it exists, and if so, is it used in aircraft?
I can't quote recent aircraft, but in the big white pointy one, the 'g' indicator ran off a one-axis accelerometer installed with the sensitive axis along the z-axis of the aircraft, hence it indicated normal acceleration relative to the aircraft coordinate system.
The accelerometer was installed on frame 56, so as close to the "average" CG as possible, to minimise pitch angular acceleration effects.
As it was, there was nothing specific about the accelerometer... identical accelerometers were used to sense longitudinal and lateral acceleration (for other systems). They were just mounted differently.
Your "g meter", as you describe it, would be "contaminated" by longitudinal acceleration or deceleration.
CJ