This is a very interesting video. I am curious (and dont want to start anything) but in a structure fire, you spray into the window openings. While the doors are open, the spray is directed to the top of the fuselage, not to the interior through the openings.
Also, in regards to the equipment, noting the numerous attempts, the range of the spray seems to leave quite a bit to be desired. It appears they have to get very close to the ac to be effective.