This situation creates a perverse incentive with the United Quest card which gives 10,000 of these restricted miles after spending $20,000 in a year. If you have a reason to spend a lot, better to get the bonus restricted miles very late in the year rather than early unless you plan to use them immediately. Of course, if you have already booked a flight with regular miles you can always cancel it and use the restricted miles if you can get the same or better deal later. Makes for complicated bookings.