To play devil's advocate, couldn't certain modifications to a heat pump damage the unit?

I'm guessing they made "happy path" decisions thinking most people aren't going to modify cycle timing, or know how to do that or what it entails. That 3 minutes was probably decided on by a group of engineers who thoroughly know the product. Especially if they provide a warranty.

You may know / understand a heat pump system but if I modified values with no safeguards on mine I'd probably break it within the hour.