Right, I know that based on these properties the air-vapor region will change temperature much faster than the liquid in response to a heat source/sink.

But shouldn't the evaporation process be adding latent heat to the vapor region via the enthalpy change, not sensible heat? The increase in enthalpy in the vapor region should not manifest as a temperature change, because it's consumed in the phase change process.

On top of this, the vapor region is going down in temperature, even though its enthalpy is increasing, which seems incorrect. The liquid region also does not show temperature change even though it's losing enthalpy.