I just realized I posted this subject twice in the Revit MEP forum. I ain't no MEP; I hope it was ok to post there. I felt like I did as a kid when I used the sugar spoon to stir my ice tea.

I figured out my invisible light fixtures would become visible on the ceiling plan if I changed Level 2 (renamed Top Plate) height from 8'-0" to 8'-0 1/2" and set my ceiling height from constrained to Top Plate to unconstrained 8'-0" above level 1.

Then, I went to Visibility / Graphics Overrides and unchecked Light Fixtures > Light Source so the fixture outlines had nice, black lines.