2 ton Carrier 38YXA heat pump.
Balance point set at 40*F

Defrost thermostat closes contacts 30*F plus or minus 3*F
Defrost thermostat opens contacts at 80*F plus or minus 5*F

1.- Given the high balance point is there any need for defrost operation at all?
2.- If there will be defrost, it will be minimal and 80*F appears to be too high for defrost thermostat reset. Are there thermostats with lower contact-opening temperatures in order to open the contacts of the thermostat before the timer calls for a defrost cycle start?