You need to use economizers to increase the sales of Carrier or Trane.
Who is funding such researches?

With an energy simulation you can show that your heatpump is as efficient as a code-required system with economizer.

in my opinion water-source heatpump are energy wasters and a maintenance hassle. For cooling, those small heat pumps are less efficient than a larger chiller. For heating you burn gas in a boiler and in addition use electricity to run the compressor. In addition each space gets one of the noisy devices that need to be maintained and replaced every so many years.
They are popular for geothermal, but even there i think having a central geo-cooled chiller and AHU and a central "boiler" heatpump is better. Do an energy simulation and you will see...