The heat pump requirement changes the economics by quite a bit because you are forced to run the pump longer than what you actually need for just circulation. I did my analysis based upon a single turnover but at 12 hours you are over 5 turnovers.

Even 8 hours per day is way more than what you need since it is over 3 turnovers. With 2" plumbing you are probably getting close to 90 GPM which would be about a 2.25 hour turnover. So you could save a lot of money just by reducing your run time by a lot and still have a clean pool. Also, the heat pump should be able to work on low speed of a two speed pump so you can save even more by changing out the motor. If you have to run 12 hours a day for the heat pump, that would shorten your break even by at least half.