Overweight?
Specific to type ODMs should certainly indicate by performance whether as aircraft is overweight or not. T/O and Ldg distances, rate of climb, failure to reach target speeds etc. Unfortunately this information is available only afterflight, and I suspect in some instances this has probably been too late! Is there such a thing in existence as an aircraft weigh bridge? Just think if there was such a thing, one at each R/W marshalling point, a little bit like the DOT roadside weigh stations. But even if this was possible you would have to have "non" corrupt operators!!