Alejandro - now that Rainboe has (finally?) left this thread, may I summarise?
You asked in #1 about a phenomonen (ice crystal icing) about which some posters know nothing because it is not in their 'drivers' handbook' Others do, including major engine and aircraft manufacturers. Good on you for asking. Please take note that it is thought to be a significant occurrence. Manuals will eventually be amended if it is thought necessary. There is information published by various manufacturers which obviously has not reached the third level airlines yet.
It is up to you how you progress this. Keep an open mind and keep asking questions and looking for information.
As a final thought, it is only in the last 20 years or so that the legal requirement for London Taxis ('Hackney carriages') to carry a bale of hay in the back for the horse has been dropped. Progress indeed. It is true that not a single horse ran out of hay in a motorised London taxi in the years the law was in place.