Because I plan to fly or have my friend /family fly on the flight so book standard economy at 70,000 miles, then when business saver becomes available at 60,000 miles I change the booking. As a 1K no fees for me using this approach.

Yes, it is a three step (book, cancel, book) rather than a one step process but I use less miles and get the desired flights. The friends/family are generally flying with me (on a paid ticket).