Doesnt matter - there is no "slack" in a geared system.. at least not the types of "sloppyness" you are trying to explain away.
Any engine with a 6600 - 7000rpm redline will at first slowly build revs from very low rpm when you open the throttle.
I completely disagree with your analysis..
It is not mechanical at all - but simply a natural stumble of the fuel/air delivery and hence power output at that point in time.
The kind of mechanical slop you are talking about does not exist except in a setup that has just been broken.
