Lightbulb/TV - opaque or unlit?

Let’s say I have a lightbulb (or a television set) in game. Obviously, when the device is on, it will have some emissive properties, but when the player turns it off, it would behave (mostly) opaque. I think I read in the Unreal docs somewhere that even though emissive materials can be lit as opaque, they should preferably be unlit because that’s cost-effective, performance wise. So, which of these two is the better approach? Do I programmatically set the material of the lightbulb to a different opaque one when the user turns it off, or just choose the shader model as opaque, along with emissive, and just control the emissive color intensity with code?

I would just use opaque, it will look fine