You need an SR/SFR compatible servo period to run those modes. You can ruin a servo if you try to run those modes with a servo not designed to run those fast modes. Just because a servo is capable of running at 1000hz doesn't mean it can run SR/SFR mode. If anyone on here wants to utilize those modes to get the maximum performance the radio can provide our servos fully support both modes, and I am sure a few others out there as well. Remember to bind in 1 way mode as well.