I think you've got it.Just to clarify...
If Person A buys an 8yr/120K mile warranty when the vehicle is brand new.
Person B could buy a ~5yr/100K mile warranty for $100-$150 more, right before they turn over 36K miles.
Is that correct?
Let's say I bought a 2017 Ridgeline 2 years and 11 months ago and it has 35,000 miles on it today. I could have bought the 8/120 "new" plan at the time of purchase for about $1,300 or I could buy the 5/120 "near new" plan today for about $1,400. Either way, I still end up with about 8 years of coverage from the day I bought it or until the odometer hits 120K. By waiting, I would pay a little more for the same coverage and would have lost some of the "side benefits" during those 2 years 11 months such as a rental reimbursement or meals/lodging if I broke down while away from home.
If you're not worried about the side benefits, it might be wise to wait until the last minute to consider Honda Care. If a vehicle proves reliable over the first three years, you might consider skipping Honda Care. If a vehicle hints at future reliability issues (fuel injectors, transmissions, etc.), you might consider opting for Honda Care at the last minute. If you wait, there's always a risk that Honda Care could increase in price significantly, but it hasn't done this historically.