I broke down and removed my OEM rear reflector earlier today. It interferred with the seat post bracket that allowed my to mount my 4D Toplight without the rack. So right now, I've got the seat wedge with reflective bits, the Cherrybomb, and the 4D. Both of the lights also act as reflectors when not powered, the 4D is more effective due to wider surface area.

I'm thinking about moving the Cherrybomb to a seat stay, putting the OEM reflector back on above the 4D, and a TBD light for the other seat stay.