static SimpleLiveValue<S> lvFlexibleRateTimerFreq(FlexibleRateTimer timer, O... _) {
  SimpleLiveValue<S> lvRate = stringLiveValue();
  optPar int delayOnInput = 1000; // how long to wait after someone typed a new frequency value (ms)
  
  embedded S formattedFrequency() {
    ret formatDouble(timer.getFrequency(), 3);
  }

  lvRate.onChange(rLater(delayOnInput, r {
    S s = trim(lvRate!);
    if (eq(s, formattedFrequency())) ret;
    Double hz = parseDoubleOpt(s), ret if null;
    timer.setFrequencyImmediately(hz);
  }));
  
  timer.onFrequencyChangedAndNow(r{ lvRate.set(formattedFrequency()) });
  ret lvRate;
}