I just tried setting the volume programmatically to a ridiculous amount. As it turns out it just played static until it got to the quieter part of the pinging sound. So it does seem there is a limit, and no sound will be played louder than that limit.So are you basically constrained by the sound API? Or are you able to manipulate the hardware directly? If abiding by Apple's API's I'd think Apple wouldn't have a problem with equipment damage at all since you can't drive the transducers harder than any other app that sends sound to them. While the confirmation button is helpful, Apple likely wants you to use the sensors to determine proximity to a persons ears ... Then again, if your AirPods have fallen between the couch cushions, that would prevent them from working.
If constrained by the API, how effective is the sound? Can you clearly hear it from another room?
They're defiantly loud enough to hear if you dropped them in between the couch or something like that. I've also been able to hear it from another room behind a closed door maybe 20 feet away.
Incase anyone is wondering I'm using my EarPods for testing because my AirPods don't arrive until tomorrow, but I don't see any reason why this wouldn't work just as well on AirPods.