I like to model simple dropped/suspended ceilings with Beams for the tee-grids and the ceiling tiles as one Slab. Then use SEO to cut the tiles.
If I need to schedule how many of each size tile there is I can exploded the slab/tiles into morphs.
The way to generate the Reflected Ceiling Plan then is with the Floor Plan Cut Plane Settings of the RCP View.
This will depend on how you have your Stories set up and what Story you have the beams and slab displayed on. Personally, when I need to make a RCP for a suspended ceiling I add a Story to the model just that.
I model the fire sprinkler escutcheons, lights, smoke detectors, grills, vents... on that Story as well.
ArchiCAD 25 5010 USA - Windows 10 Pro 64x - Dell 7720 64 GB 2400MHz ECC - Xeon E3 1535M v6 4.20GHz - (2) 1TB M.2 PCIe Class 50 SSD's - 17.3" UHD IPS (3840x2160) - Nvidia Quadro P5000 16GB GDDR5 - Maxwell Studio/Render 184.108.40.206- Multilight 2 - Adobe Acrobat Pro