Re (But it was because of Safety Dave large screw on sensors that caused the valve to fail in the first place as they do not fit in the recess of the rim and the valve are distorted)
Re Sensors that screw onto the valve stem.... Ensure that new Valve/stems are replaced with every tyre, sometimes this is not done and the weight/G force of the sensors (at speed) can cause the tyre valve to leak.
Have posted this previously, but A small length of 13mm soft/ ld/ garden poly pipe takes up most of the slack between rim and tyre valve, cut to suit your rim so that it finishes immediately below the screw on sensor.