i have a rotary,
yes they can ping, its not ALLWAYS loud.
but yer pretty much dont expect one to tolerate alot of pinging.
you also need to remember the scenario usually goes like this:
ping>broken apex seal>hard apex seal score inside of housing as motor spins>apex seal shoots out exhaust port into turbo>turbo gets ****ed>apex seal goes back into other rotor housing if unlucky>scores other housing.
your left with allmost nothing reusable... they are very reliable, but i wouldnt call them durable if you **** up your tune, they can die very fast death.