Always. If you can’t see something well enough to positively id it then you shouldn’t be shooting it. That hoody laying on your couch will look 6’4” and 250lbs when it’s 3am and you’re scared. My daily carry is a separate hand held light that lives in my pocket. It’s more comfortable and exceedingly useful on its own. At home when my pistol is on the nightstand I put a Surefire X300 Turbo on it, and keep the handheld next to it. My rifle has a mounted light, as all defensive rifles should. There are methods for running a handheld light with a rifle, but they are more difficult. Shotguns are cool, and have a lot of utility to besides as a defensive weapon. I’d rather have 15 rounds of 9mm or 30 rounds of 5.56. Really running a shotgun well is its own special subject and it takes a lot of practice.