[quickthrowman]

> Wouldn't homes just benefit more from replacing their existing furnace+AC systems with a heat pump if it's necessary, rather than installing mini splits in each zone and running refrigerant pipes all over the outside of the housing structure.

Yes, if you have an existing forced air system you can get a heat pump sized for your furnace instead of doing mini-splits. You could probably just replace the condenser with the heat pump, since a heat pump is just an air conditioner that can run in reverse. The coils inside the furnace may need to be replaced for the heat pump.