To use RFP you need to have a PC connected in your production environment, is that really what you want? Also your hardware needs to provide a USB connector which might be planned or not. There is a device from Segger called Flasher portable and it might be just what you need. Manufacturing environment friendly, a small device that will only need to be connected to a PC one time for setup, then you connect to a target hardware vie JTAG (or JTAG footprint) and push one button to program. In fact you can even store 4 different binaries in the little device. OK, RFP will probably be included in the Renesas deliverables by the time it will be available and Flasher portable is about $500 but it would be ideal for what you are looking for.
Give it a thought as most PCBs have a provision for debugging anyhow, this interface could also be used for flashing, no need to expose USB (for programming).