[voidwtf]

This article was not about using web sockets, it was about using a standard HTTP stream in a somewhat unorthodox way by never completing the request. Instead just beginning the response and occasionally "flush"ing data in the buffer to the client. The problem is that you'll often run into middleware that will do one of the following.

I've personally encountered WAF proxies that will wait for the request to complete before sending any data to the client, that means that the client would appear to receive no data until the request timed out or the server completed the response.

I've also encountered MITM/DPI and load-balancing proxies that will do the same, waiting until a buffer is filled and/or the response is completed.