As far as I can tell, there is currently no method to arbitrarily query a client's mouse. To retrieve stuff like what atom it's over, its onscreen location, etc.

I know there are push procs we can override to recieve information whenever these change, MouseMove being the most notable one. But the documentation indicates that these are optimised out if not compiled in, and the idea of having a proc called every time someone moves their mouse a single pixel is too much for most servers to want to use it.

We need a way - entirely outside of these procs, to ask for the current parameters of the mouse. These don't even need to be cached on the server, it could send a query to the connected client and return a value asynchronously