Since I cut the cable and put an ATV4K in place of all the stuff, I find myself in the same situation. The only thing I require is my RFX9600 emulator which accepts 1-way relay actions and serves as a power-sense for the TV.

Basically, all my input ports on my emulator reflect the state of the corresponding relay On/Off. I also use a software serial port in loopback mode to allow me to do progress bars and send messages to a listening page during system startup.

I could have done the same thing with relays/inputs on my real RFX9600 but I determined there's no use in activating a hardware relay for this purpose as it only wears the contacts and the coils.