Within the confines of a home you really don’t have to flag the muzzle around much to illuminate the interior enough to ID threats. You can pick areas to illuminate that you know no one who belongs there will be in the path of that potential round, and hit the light. Between how wide the beam is on the light and the light reflecting off of the room, you can usually light up that room pretty well without needing to sweep it at all. Unless you live in a giant warehouse, if you live inside a giant warehouse you’re probably going to have to sweep a WML around if that’s all you’ve got. Just try it with your handheld light instead if you need to sweep the beam around to search for an intruder.
It will take training and practice just like anything else, and I’m certainly overdue for some myself, but if you go get instruction on both hand held and WML you will never want to shoot with anything but the WML if you have a choice. By all means have a handheld light for your non firing hand, there are methods to retain it so you can use that hand without dropping the light. Of course if your home defense rig is a shotgun or carbine it should 100% have a light on it, and you 100% need to train in your own home to use the spill of that light to illuminate rooms in such a way you don’t point it at loved ones known (probable) locations. The advantage is it’s your home, you have access to it to conduct this training any time you want to, as much as you want to.