currently in foreverFrame.js, in start function:

        if (window.EventSource) {
            // If the browser supports SSE, don't use Forever Frame
            if (onFailed) {
                connection.log("This browser supports SSE, skipping Forever Frame.");
                onFailed();
            }
            return;
        }

Since we just disconnect the connection when it is not supported, so it is better that the log message update to say like:
This browser doesn't support Forever Frame.

And we can also remove the the check on if (window.EventSource) in this case.