the fitting that goes up the pole is so i can connect/disconnect from the main hose
i have a small hole that i feed hose thru in side of van so i only set up once a day and dont have to lift reels in and out, i just put pole on roofrack in between jobs.
having 2 angle adapters is instead of paying silly money for a gooseneck it also lets me interchange between brushs if im doing upvc cleans etc.
as for worrying about moving from window to window the amount of water used is not worth worrying about it takes 2 seconds to move to another window
i am faster than any other method.
i am often doing jobs twice as quick as other guys fannying around setting gear up and packing away again in between jobs
ie trailers, backpacks, trolleys etc
i pull up take pole off roof and am working inside 30 secs
when done i use a drill to wind in hose 20secs
then im off to the next one.