The harmonic notch filter is really magical for me, today I made three test flights with a new tuning,
1.- The noise similar to a bee hive has disappeared.
2.- The abrupt drainage in battery power consumption has disappeared.
3.- More flight time (about 2 more minutes).
4.- Smoother control on all axes.
5.- More precise vertical and horinzontal displacement.
I get all these advantages, no matter that my flight controller is fixed to the frame without damping foams.
The problem related to altitude retention has improved a lot and now I am sure that this is due to the fixed mount of the flight controller.