So, I recommend that that section of the EWMH be gutted and rewritten
(I'll provide text if there is consensus that this is correct, though I
haven't yet re-figured-out the parts about compensating for
border_width), with a note pointing out that (a) a previous version of
the spec recommended the wrong behavior, and (b) pre-EWMH window
managers have differed in how they interpreted this anyway, and so
therefore Clients SHOULD always include x and y coordinates in
ConfigureRequests and _NET_MOVERESIZE_WINDOW requests for windows with
non-NorthWest, non-Static gravity, to ensure that they get the behavior
they want.