Ah, I see your question.
"72 minutes" should not be transcribed in Nemeth switch indicators. Nor should "72 hours" "72 seconds" or "72 pounds", because the simple numeral "72" falls under the exception described in 3.a under Basic Guidance on When to Switch in the Guidance.
It is not the unit that determines whether a value is technical/mathematical. We determine whether a value is technical/mathematical and Nemeth Code switch indicators are necessary based on what comes before the unit of measure. A decimal, for example, does necessitate Nemeth switch indicators.