Join Date: Oct 2000
Location: SEA, or BOS, or MUC, or other places (probably connecting). "Detroit, Michigan is in the Eastern time zone."
Programs: DL GM/1MM, NEXUS/GE, CLEAR, Bonvoy Platinum, Hilton Gold
Posts: 1,210
Technically, nothing will "ensure that PreCheck will be provided" as the TSA can always just decide not to give it to you even with your KTN and other info provided in advance.
That said, I am batting 1.000 on Pre-eligible itineraries since getting NEXUS across three airlines (DL, UA, and B6) even though I only have status on DL.