Maybe there’s one other thing that you can try. My block is a concrete slab construction (late 1990s), and my apartment has two layers of gyprock ceiling suspended from the slab by about 25mm.
My upstairs neighbours at some point installed Ikea flooring (of course no permission, and then the apartment was sold), but because of the air gap and the two layers of gyprock, I was actually none the wiser until I saw the photos on Domain.com: occassionally I can hear noises, but that set-up certainly mitigates most noise….it may be worth considering, and, if your OC is so frightened about things ‘on the record’ perhaps they will pay to retrofit your apartment.
You will loose some ceiling height, but you may gain some peace and quiet.