Bradley, Qantas and AIPA did exactly that a couple of years ago and the results formed the FRMS report published by the University of South Australia last year. The report is supposed to form the basis of FRMS based duty limits for long haul flying, but the airlines suddenly don't like what it says about the fatigue levels of the pilots flying their aircraft, particularly on ULH east-west style flying.
It will be very interesting to see what happens.