Very nice sheet. I especially liked the part where you have the huge formula and just note "we assume the situation's mostly identical, therefore".
Sure sign of a pro.
Might it be beneficial for the sheet to have some graphs if it were to be used as a testing template? I played with some plots but didn't come up with anything I'd consider too useful (like, a scatter plot of accumulated incomes of order/growth with different values or something...). Might not be a worth the trouble, especially if you intend to use the sheet just to bash your point in.