Did you read the disclaimer?
The DPS values you plug in aren't tested. The resulting stat caps are predictions offered by a proposed algorithm.Stat caps are calculated as a logrithmic curve of wDPS, based off of known data values. In short: It's imperfect but it's the best that can be done for wide-spread usage.
Also:
The current version is lists the cap for Ifrit weapons correctly at 350 STR, something which has been tested and shared, and is probably the only stat cap for which the community has any certainty.Version 1.23 - Crit calculations updated, Fixed Slight AP from STR calc error, Added Stat Caps, Added player stats. Fixed Calc Error with Item Rows 4 & 5. 7/30/12
The stat caps in the latest version are possibly closer to ideal, but the spreadsheet is not a compilation of test results for DPS values; it remains a predictive algorithm.
The short of it is this: any weapon released after Ifrit's Claws, with the possible exception of Giantsgall, will have a stat cap of at least 350STR and 310 INT.