Ceiling Panels in a normal room, have you tried them?

Try 3M  Command adhesive hangers-blends in since they're white(assuming ceiling is) don't look ridiculous, and can be removed with no mess.

Attach an eye hook setup on the back of the  damping panel. They can be put into place in minutes/removed easily. In 10 minutes you can have  the entire ceiling look like a recording studio.

At my parents house in the 70's I attached and suspended a surplus parachute from the basement ceiling . It did help the sound in a room with Maggies and looked kool with lights in between..those were the days..Tom

I use a 6x4 feet 8 inch thick "cloud" made of Roxul safe n sound placed at the early reflection points on the ceiling

The "cloud" was the last early reflection panel ive put after installing my sidewalls and behind the LP.

Its a obvious and wonderful upgrade to any system

I use drywall angles on my ceiling to redirect energy off the ceiling and wall junctions and towards the listening area.
I have built a multi angle acoustic lens on the ceiling in which the movie screen retracts. The lens is hard mounted to the ceiling. The lens has 5 sides. The 2 sides share a common angle, front and back are different from each other the  downward facing bottom is at a narrow 90 to minimize intererfering energy. Tom