On the types i'm rated both flow and microphone can be tested while the mask is still stowed. And yes, we have to do that before the first of our flights of the day of course. But regularly taking the mask out and use it is not part of the normal test, and since we do not have to use it during normal operations re-stowing isn't trained, let the engineers handle that, it is part of their job. It is the same in the simulator. Use it, roughly place it close to its stow position and let the simulator engineers stow it after the session. My company pays for that after all.