Annoyingly I never got around to measuring the room before we moved everything out to do work, though I think there will be an opportunity to do that before installing rockwool. The stretch ceiling is a one-time thing, once it’s up that’s it, so it’s a case of working out how much rockwool to install above…
Depending on how much height you can lose, you can get good results with an air gap ie mounting the trap away from the hard surface.
The wall/ceiling is a null point, so there’s more energy to absorb if you can move away from it.
Annoyingly I never got around to measuring the room before we moved everything out to do work, though I think there will be an opportunity to do that before installing rockwool. The stretch ceiling is a one-time thing, once it’s up that’s it, so it’s a case of working out how much rockwool to install above…