Agreed.
Raw pace is scary on the BGP's though. On long stints (20laps+) they are still pilling as fast/faster times than the rest, which is a better indication than the (admittedly good)glory runs.
F1 cars are engineered to be well underweight then ballasted to meet the regs (meaning the teams can move the ballast around to change the cars handling).
Even without taking fuel level into account all they'd have to do is not fit that ballast whilst testing and they'd be able to do long runs and 'race simulations' whilst still turning out an impressive looking pace.