It seems that Comcast has tweaked things on their end so that all versions (past and present) of the xfinity Stream app crash if loaded into the Android TV OS, but has anyone found a web browser that can be sideloaded that runs the web browser version of xfinity stream well?
https://forum.xda-developers.com/android/apps-games/xfinity-tv-mod-android-box-hdmi-output-t3535881
Read through that thread. The info on page 10 works for me using the Canadian (Shaw) version of the app.
Previously I had tried to get it working in a browser but couldn't get it to work. Needed Flash to get the page to work, and the only version of Flash that works is older than what's supported by the web app.
That would be great. Until then, we'll have to cast it from our computers.