OC: I’m sorry if you object to the halacha or what the Rabbonim said. But I answered your question three times and you keep re-asking it, so you apparently don’t like what you are hearing. For the final time, they said it must ALWAYS be covered under ALL situations irregardless of how long it needs to be to reach that objective. (Regarding highly unusual heavy winds, you are not held responsible for something that you couldn’t anticipate.) But it must ALWAYS cover you when sitting, walking stairs, entering a car, and every other daily situation.
As far as the inches, there is no hard halachic number. Some people will need even more than 4″. They simply stipulated that it should ALWAYS cover you at ALL times throughout the day, every day. YOU said earlier (see your comment beginning with “Im not denying anything”) that you need at least 4″ to reach this point. Some Rabbonim may tell you a specific number that is minimally necessary to insure full coverage at ALL times and others will simply tell YOU to make sure it is covered at ALL times and have you figure out how many additional inches below the knee is necessary to achieve that goal.