Manually switch to emergency heat?

Hello, I recently had a new A. S. heat pump system installed at my residence. After installation, the technician told me that if the outside temps dropped in the 15 degree range, I would need to switch the system over to emergency heat or the outside unit would lockout and I would have to reset the unit at the breakers on the air handler. Sure enough, the temps last night dropped into the low teens and I awoke with the outside unit not working. After resetting the breakers, the unit came back on. I told the technician this did not seem normal to me as with my other heat pump, i could just set it and forget it. His reply was that because of the new refrigerants they were required to use, the outside unit would lockout in very cold weather and that i needed to switch it over manually if the weather forecast was in the teens. I would not have bought the system if I would have known this information beforehand. Is this information correct, and if so what can I do to make the system a set and forget it system?

source https://hvac-talk.com/vbb/threads/2236025-Manually-switch-to-emergency-heat?goto=newpost