I don't even think you need to indicate direction of motion or motion or anything .... i mean drivers have eyes and cars have headlights. he idea is to catch a driver's attention so that s/he will know to pay attention. That is why flashers are so good---the brain latches on the changing situations where a seemingly steady light is more easily ignored. I'd say spots around a wheel are just as good as a whole wheel because if the driver is coming at you from a side street and can see the wheels--i.e. you are passing in front at a 90-degree angle .... then the driver is either stationary of milliseconds from hitting you.
I have ridden up on vehicles in driveways---full lights, Bright lights---and twice had them pull out, almost hitting me. One was an extremely close call .... I imagine the guy was checking his phone for directions, decided where he wanted to go, and just headed out, coming within literally four inches of crushing me. The other I sort of expected it and slowed .... which was a pain because it was a long hill and a fully-loaded bike, but as I expected, the idiot driver looked right at me and pulled right out.
Fully lighted rims would never have been visible in the time when the driver ---and I--were making the decisions which would have sent mass into motion, and once the masses are in motion, their vectors cannot be modified that quickly ....
So, what is needed is probably two headlights .... one normal, and one at a 45-degree or greater side angle so cars on side streets can see you coming, plus an air horn, to shake them out of their phone-induced dazes.
No specific lighting system is going to help if they don't notice you, or put the car into motion before they see you.
Real safety comes form using all the tools to tilt the odds in your favor ... and then riding like you expect people to pull out into you. That is what has helped me avoid death and destruction, and when I failed to assume the drivers were idiots, I have nearly died for my own idiocy.