I run with my NiteRider Pro 12E taillight blinking night and day. It’s the only LED taillight I’ve found that is visible in bright daylight.
The Pro-12E headlight has a strobing feature that’s designed (they say) to attract attention. You can set up so that the headlight is off and the taillight is blinking until you press the control button to start the flashing.
I run with the headlight off until I come to an intersection or a door zone where I want to become more visible. It’s also useful when you are on a two-lane road and someone coming at you makes a wide pass. I hit the light to let the driver know that the oncoming lane is occupied.
I’ve had a couple of cops do U-turns to talk with me. Instead of the expected hassle, they’ve complimented the long-distance visibility of my bike.
I’m a big proponent of lights, but it might be because Missouri drilled “Lights On For Safety” into me when I got my license back in the 60s.