Instead of basing your “home internet” on the xfinity account number, you need to base it on service at the address. I’m a senior software engineer and I have to work from my house often and thus require the use of Comcast business internet, but use xfinity for cable television. However everything is disjointed and asks me to connect to my home WiFi when I want to watch certain shows online - which I cannot do because I have business internet.
I know that business and xfinity are two different entities of the same empire, but you both have my home address and can share that info to know who I am... you should even be able to check the status of my account between the two. Just write a simple proxy program. Either way, I am sure I am not the only one in this boat. Thanks.