Xfinity Port Forwarding is garbage

I just want to connect to the Xfinity modem/router and configure port forwarding manually. I don't want to use your phone app, and I don't want your overly clever router only offering a list of computers & devices it can currently see by arcane names or MAC addresses! It's stupid. Stop it! 

I want to enable port forwarding from the WAN interface, define the destination IP address on the LAN, protocol(s), and port number(s). If I have to define the ports by first creating a "service" so be it, but give us the option! 

FYI 

I am an IT network consultant of over 40 years, I've published books on networking and internetworking and many articles in many publications over decades, as well as conduct thousands of networking seminars internationally.