Yes, but there are ways of dealing with inertia. Like making the door lighter and putting padding on the contact surfaces. It's not rocket science. Also, most

Yes, but there are ways of dealing with inertia. Like making the door lighter and putting padding on the contact surfaces. It's not rocket science. Also, most of the improvement would come from replacing the worst offenders (5-10 second closing times) rather than from shaving 1 second times to 1/2 a second, and there's tons of precedent for the former from the faster-closing 10% or so of existing installations.