Take of acceleration
In Jaguars on hot and high days we had a speed check at every marker (300m) and at the middle marker if we didnt cross above a certain speed, it was mandatory to reject. we had a couple of airfields at very high altitudes where take offs were really hair raising.
The similar for landing at the middle marker we had to be less than 100 Kts or we would deploy the tail chute.
There are accelerometers available linked to the INS which could be checked by the PNF about 2-3 times and if the acceleration drops below a certain value than one could be warned. In addition this would help during deceleration on landing.