I am developing an app that will run with an HDTV as its display. Is there a way to set Designer with a target layout of 1920x1080 (maybe a "custom" option in the Layout list)? I tried selecting "Match Connected Device" but that didn't work.
Yes. You can create a variant with any size you like (press on the New Variant button).
You should then select Match chosen variant in the abstract designer.