No SR is doing the opposite.. it is like a balance on the sensor.. moving up and down, left and right to counter the micro movement of your hands in order to minimize the blur induced by hand holding. I would keep SR on pretty much at all times if hand hold shooting.
The only time I normally disable SR is on a tripod but, if you use the self timer (and I would recommend if shooting on tripod against a landscape), the camera automatically disables SR.
That is to say, yes you leave if off when you don't need it. However, you generally need it at all times hand holding (unless you are shooting fast above the threshold he mentions in the video).
That said, try practicing with it. Maybe you have amazingly stable hands. I once shared here on PF that I can hand hold with SR on at 300mm 1/60th and some claimed I was lying.
The general threshold has been recip of the focal length for FF or double for crop (as indicated in the vid) so I'd need 1/600 without SR.
That is to say, my image was sharper with SR on at 1/60th than it would be without it since I couldn't even come close to 1/600th of a second in the lighting situation I was dealt. I suspect in most cases you won't be shooting at telephoto range in bright daylight and thus are not afforded the option of disabling SR when hand holding.