That may be right, however it is irrelevant in this case.
pevh was the one that brought that idea that donut farming being exponential to this conversation. That was a concerned raised by him/her and not by anyone else.
For the vast majority of people that farm donuts, being exponential or not is completely irrelevant. What they want is to grow their multiplier in order to get more bonuts to buy more premium items. That's why they donut form. Period.
We've seen multiple cases of people in the last few days that say they've stopped worrying about the multiplier because they can now buy everything they want or that they have started storing multiplier items because they want their town to look nicer and they have a large enough multiplier to allow them to do that. We've never seen anyone saying that they have stopped farming because they've realized that the functions are not exponential.
If there is a limit on your multiplier, if the growth is not exponential, or there is an "optimum" is completely irrelevant for the vast vast majority of donut farmers. And just because someone claims that they have discovered the "truth" (despite the fact they refuse to share it with us), won't make it relevant for those players.
