Room is now properly masked at the ceiling. In a painting project the bulk of your time is spent preping the room with masking and trimming out the edges. I procrastinated putting the masking tape on the border using "the blue paint has to cure" as an excuse but really I was avoiding it because I exaggerated the tedium in my head.

For painting use Ready Mask Painting Tape instead of traditional masking tape. It goes on strong but doesn't remove paint like masking tape that is left on too long would.