There is a mild sde but it doesn’t look like the regular one most are used to. If you get a very stlill scene/pic if you concentrate you will see rainbow shaped arcs. There is a post long ago describing it with a pic reference.
You could do this experiment: try to augment the supersampling, open virtual desktop and try to read a web page from there. Then try to zoom in and out. You must see that the page if isn’t too zoomed in is not so clear as in your monitor. This is why you could not use your HMD instead of your monitor: screen door effect and low resolution are too high in every HMD actually.