Do inserters extend/retract unnecessarily?

[T__C]

I'm trying to get precise behavior out of some inserters, but my timing is off by a little bit, and I'm trying to figure out why. I think I know the answer, but I want to check with the experts here to see if I am correct. My theory:

When an inserter is idle, it extends/retracts its arm to a neutral position. Therefore, when an inserter drops a tick below 100% capacity, its throughput undergoes a step change downward because it needs extra time to move into the neutral position and move back again when the next item comes along. Thus, an inserter which can handle x items per minute might not be able to handle the slower rate of x-∆ items per minute.

For an inserter designed to pull from both the near side and far side of the belt, there may be a use case in which this behavior is desirable. For inserters designed too pull from one side only, however, this behavior is pure waste.

Am I correct in this analysis? And if so, is there any way to modify the behavior? (e.g. Is there a mod for this?)

-TC