The article reaches the conclusion that the best way to handle the situation is for the display server to provide the dpi primitives and let the client figure out how best to draw to that dpi. But acknowledges that there is a hack where you can make the server present a standard scaled dpi, but the drawing will then be bad. And there is this new-fangled thing called wayland where all it can do is the hack.

The irony is that wayland is infamous for usually making the clients do the work(I am thinking window managers) and X for providing a standard method. Nether of which is true, but it made me chuckle.