As far as I'm aware, the proposed mechanisms for this have to do with the distance to the focus point -- in other words, the fact that the display is close, not

As far as I'm aware, the proposed mechanisms for this have to do with the distance to the focus point -- in other words, the fact that the display is close, not that it's a display. The virtual distance to the display, and hence your eyes' focal distance, is definitely something you can change in VR, and presumably also AR, so I think this would actually presumably be better, wouldn't it?