I did use my extender almost daily, at an average of 4 hours per day, and during the first 2400 hours, I gained about 1 1/2 inch. Due to different things, I took a long break - some years without regular PE work. Did not loose anything of the gains, and have started up again a while back, and are gaining again - very slow, but it’s there.
Then a word of caution; do not use any equipment that hinders bloodflow during sleep. The only thing I have used at night is an ADS of the variant where you have a leather piece tied to the penis ( not too tight - not to hinder erections) and the leather piece is attached to a string that in the other end is attached to a strap that goes around my leg below the knee. It gives a nice easy stretch, that I can have all night, and wake up with a 6 1/2 inch flaccid. Do not use your extender at sleep, no matter the noose version/comfort strap version/ or vaccum version.