My understanding of heat pump operation in the heating mode is that the function of the evaporator and condensor are reversed from that of a standard AC system, and therefore the flow is reversed in the refrigerant lines.

Shouldn't the liquid line be insulated in a HP system then to extract the maximum amount of heat in the indoor coil which is now acting as a condensor? It seems that some HP installation manuals specifically state that the liquid line remain uninsulated, and some only talk about vapor line insulation?