The problem is the proliferation of frequencies that can be used make the environment very difficult to predict. Especially with some of the things appearing which can have second harmonics in the radio altimeter band, and have fundamental signals in the surveillance radar band.
Probably the best answer would be to fit the aircraft with a multi band jammer for all mobile bands......
The situation gets more complex as the aircraft gets older. Cables flex, and the screening gets partially broken and so the immunity is reduced. So a 'good' aircraft can become a 'bad' one over the lifetime. You can get enough problems from the radios fitted to the aircraft, let alone extraneous ones.