Help with Quest "Standing at the Helm"

[Niwashi]

If, for a given recipe and stats, you get 100, 110, 121, 131, 142 for the first 5 Touches, why would you want to GS the 100 (bringing it to 200) when you could GS the fifth (bringing it to 284)?

Because it can usually get you a condition based crit on it (not guaranteed, but it triples your chances), bringing the 100 to a 300 or sometimes 800.

If you have enough extra CP to add in a couple Observe steps as well, then you can get the same crit chances at the end when you a better IQ stack. (But by the time you have that, it's almost enough for a second Great Strides anyway.) When I first worked this out, I didn't have the enough CP for the extra Observe steps yet, but the Waste Not and Steady Hand that I wanted in play anyway could serve as Observes at the same time without spending any extra CP.