After download, I only looked at the empty surface and checked how plugins UIs look: that all looks fine here so far.
But when I loaded a project now, I saw the same different/blurred white border lines as you have them in your photo. That’s definitely something they still have to work on. It seems to occur while zooming in an out, in some zoom stages, and is only a slight irritation to me.
While I definitely dislike that, I can much better work with the present state of things than with what we had before, when I only had the choice between eye strain or massive space waste (or no Hidpi at all).