I think the big issue is the different "tuning" for each heat pump system. For example, a heat pump water heater needs a different maximum temperature than an air conditioner, and has much different cycling behavior. This leads to very different design decisions, including refrigerant choice, pressure, compressor type, whether the refrigerant loop is even serviceable, etc. (Some appliances operate at a refrigerant pressure so high that they require being fully assembled at the factory, which would be a non-starter for a manifold system like we're discussing.)
I think this might eventually become a thing once science gets us far enough that there's an "obvious" refrigerant choice for most applications, but we definitely aren't there yet. There are hundreds of different kinds that perform better or worse in different applications.
AFAIK all of the big commercial systems that do multiple different types of heat transfer use water to do it, thus bypassing the entire refrigerant selection issue. Right now the most advanced we can do is VRF ("Variable Refrigerant Flow") systems that can individually select air handlers for cooling or heating (i.e. move the heat from one room to another). These are still commercial units and not really available for residential installs.
I think this might eventually become a thing once science gets us far enough that there's an "obvious" refrigerant choice for most applications, but we definitely aren't there yet. There are hundreds of different kinds that perform better or worse in different applications.
AFAIK all of the big commercial systems that do multiple different types of heat transfer use water to do it, thus bypassing the entire refrigerant selection issue. Right now the most advanced we can do is VRF ("Variable Refrigerant Flow") systems that can individually select air handlers for cooling or heating (i.e. move the heat from one room to another). These are still commercial units and not really available for residential installs.