paramount plus

I have for months been having similar issues to everyone else with the Paramount Plus app in my Xfinity TV box.  If this were Netflix or Prime Video or Disney, I could work around this kind of issue by using the native smart TV apps for those, which access the internet directly and bypass the Xfinity box.    Unfortunately, however, Paramount in its infinite wisdom has chosen not to make their smart TV app compatible with sets more than about 3 years old, and all of mine are from one year before the oldest supported version.   (I had to buy them all at once because their predecessors were fried by a nearby lightning strike.)   There is another option, in theory.   I have a subscription to Prime Video, and they offer access to Paramount Plus via their "Channels" feature, so I could subscribe via that route rather than directly with Paramount.  However, I am under the impression that there is some sort of contractual agreement between Comcast and Amazon so that this would not be permitted -- I thought I remembered seeing that somewhere.  Am I correct in that belief, or would using Prime Video Channels to get to Paramount Plus be an allowable workaround?