I know this to be true because I taught, and wrote instructional papers on, these systems. Prior to shooting an instrument approach, one must review the approach and set it up. If your directional gyro is inoperative and you're relying on the magnetic compass, you can depend on it only when the plane is straight and level in unaccelerated flight. If you're heading in an easterly or westerly direction and you accelerate, the compass error is predictable. Accelerate and a turn to the North is indicated.
Deceleration indicates a turn to the South.
A ccelerate indicates N orth. For years, flying my Cherokee Six with fixed gear, fuel injection, four tanks, and constant-speed prop, the mnemonic TEMP served me very well. This little memory jogger worked well until I started to fly retractables occasionally. I hated to part with my old crutch that had protected me all these years, but I realized that a reminder of the landing gear was an absolute must. For taxiing control positions.