I think traffic shaping is very desirable when using a websocket for a separate command-channel. The last thing you want is an upload blocking all communications over that command-channel.<p>Furthermore, browsers can open only a maximum number of connections at the same time (I believe the maximum on some browsers is even just 2). What if the application already uses one connection for a websocket? Will there be only 1 connection left for the upload? And what if the browser needs to download other resources in the background, such as images, fonts, etc.?<p>Just some concerns, good luck with the project :)