Wouldn't this just be a matter of adding a component at the page level which calls the Phoenix Socket function? This should be framework agnostic since the post you linked above just works with React.
It works with react because phoenix framework can send request response with websocket rather than api, I'm thinking of replacing Phoenix with RedwoodJS.
Rails also has websocket support but those are not as performant as Phoenix
I am thinking of implementing something like: https://www.viget.com/articles/phoenix-and-react-a-killer-co...
Would it be feasible in RedwoodJS with or without websockets ?