Do two-stage compressors offer both two-stage heating *and* cooling?
A heat pump is an air conditioner that has valves that switch the flow of the Freon so in the winter the condensing could is the inside making heat inside and cool outside (trying to make a simple explanation).
So if the compressor is 2 stage it can run at 2 different levels, depending on brand the compressor doesn’t know if it is heating or cooling the home, except for the defrost cycle. So if it is 2 stage it should be able to do it in heating and cooling, how effective it will be depends on the air handler and if it is multi speed.