Worked with no drama, for me at least. Hooked it to my TV because that was most convenient. USB-C to HDMI adapter, I just had to tell it where they were in relation to each other and set scaling on the TV. Fonts look a little screwy on that dialogue box, but only in the screenshot - and when composing this post I realized even there they look OK if I don't view that part of the screenshot on the 4K display.
Edit: No, untrue. I think I had the wrong glasses on. The fonts on the 1080p display are fine in reality, but the screenshot is distorting everything on that panel a bit. Again, screenshot only though. All good otherwise. I can't see any other problem after using it a bit like this though.