Given the same circumstances of DOA, DAS, Sp3, & SpA1 for 1dk, 2dk, and 3dk games, would you hit the 16 against dealer Ace using the same indice?

I ask because Canfield suggests standing on TC9 across the board while May proposes always standing on 16 in 1dk games. Are these systems "passing in the night" or am I grossly misinterpreting what they say?

My intuition tells me that there are different indices for different games. In a 1dk game I certainly wouldn't want to hit the 16 at TC8 while I might do that in a 6dk.

Are different indices available for the different games? If so, please point me in the direction of these higher truths.