Fuse 47 resets the "adaptive learning for automatic transmission equipped Mustangs. It does nothing for manual transmissions, as they shift whenever the driver shifts them.
Adaptive learning has to do with the type of driving you do on automatic transmissions (a.k.a. "shift memory"). Over time, the PCM (or ECU) "learns" your driving habits, such as you driving more city stop and go verses highway driving. It sets the shift points to obtain better fuel mileage. The problem can be when you do lots of city stop/go driving, the automatic transmission shifts at a lower speed, so the PCM/ECU remembers this. Then you go and do some 'sprited" driving, and the automatic transmission shifts too soon for your liking.
This fuse/circuit breaker does not affect any tune you have installed; you will not need to re-install your tune (if installed) if this fuse/circuit breaker is removed and installed.
So what some automatic transmission owners do to wake up the automatic transmission shift points is to remove this fuse (actually a 30 amp circuit breaker) for a few minutes, forcing the PCM/ECU to have to re-learn the shift points.
I do not believe there is a tune made that over-rides the fuse 47 symptoms. Even with firmer shifts that a tune may provide for automatic transmissions, the PCM/ECU will still learn the RPM range of your daily driving habits and set them for automatic transmissions.
It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.