UR242 - use of Hi-z to Lo-z button

Hi guys
On my UR-242 Audio Interface, when plugging in my electric guitar and pressing the Hi to Lo-z button really doesn’t make any difference to my signal.
I would like to ask if anybody knows if using this button is absolutely necessary, or does it have to do with cable length since my cable is 3 meters. I really would appreciate if someone can explain the pros and cons of using the Hi to Lo-z button.