@Frank Glencairn you have a NDA with your own project? Never heard of that! Look, my problem is that I have serious doubts on you and the other guy being capable to engineer hardware and program a software to show hdmi input with focus peaking, lut etc.pp. yourself.
It's not a trivial task. Let's assume for the project crrdibilities sake you are not just relabeling an existing product but you are working with some Taiwanese manufacturer (i.e. Febon) and they agreed to modify their design to your specs as for the hardware and some people that are engineering the software... Why is it so hard to say so, I guess it will rather make people trust more in the project than if you and the other guy pretend to have done the engineering and programming on their own. And BTW since at that pricepoint the hardware company can not use fpga's, it's going to be an ASIC, how many HDMI to h264 Asics exist, it's not so hard to find out which one they could be using, also the tech specs of the ASIC will certainly specify the design inherent latency of the (h264) video encoding, which you fail to mention in the project description. This part is influencing the latency indepenfently of the phones speed and could already be specified.
And being a bit more specific about how you are going to solve iOS lack of UVC drivers would be interesting.
(see https://stackoverflow.com/questions/32133699/is-it-possible-to-connect-external-wired-camera-to-ios-device)