You're correct. However, the special firmware for the conversion, which is the 1st step of the 2 step process to have the Pro supporting a secondary camera, is not on the support page. I'm talking about the "LDGCX2P.BIN" firmware.The SGGCX2PRO+ “plus” firmware was recently loaded on the support page. It includes the conversion instructions.
Thanks for the quick reply, I'll send a PM for the draft version.
@jokiin, Thanks for the info, I'll probably have to bring the heat gun to the rescue with a power extention coming from the house since I have no garage.