no. you don't need a format to switch between active and passive. The config is the stuff you can configure on the UI - password, satellite, wifi details, etc.
active, passive, on the other hand, is part of the image. When Ken wrote the passive-antenna image over the older one, his config carried over...and as long as he remembered to use the correct rf port for the passive antenna, his system should be (barring unforeseen issues) fully operational at this point - correct satellite selected, wifi connected, everything.