If possible, get an avionics tech to open the control unit and adjust the flash-rate timing components (usually some sort of simple oscillator like a relaxation oscillator or similar) to increase the flash-rate to somewhere within the approved range.
Strobes are not complex electronically. An inverter or DC-DC converter, rectifier, voltage multiplier, dump capacitor across the tube itself, trigger-transformer and trigger cap charged up by a charging circuit and usually an SCR and our little oscillator to fire the trigger cap through the trigger transformer to cause the tube to ionise and therefore discharge the dump capacitor straight through the tube - usually shutting down the inverter which then starts up again, charges up the dump capacitor and the whole cycle repeats.
The timing components of the oscillator circuit determine the flash-rate, as long as the time constant for the dump capacitor is short enough to allow full charging at a higher rate. Usually this is not a problem.
Might be the easiest solution.