One of my client apps will be authorised for subscriptions only (i.e. only websocket connections allowed by the server), but I may wish to make use of introspection [admittedly I am still investigating how much to use that though, and in what ways].
It would help me (!) to be able to send a query over the websocket rather than http.
Not at all a show-stopper for me - it's not too much to work-around if necessary - but could be added to roadmap for the future perhaps, if you feel it could be worth including.