I have read your all your comments with interest, because this was also an issue almost 36 years ago when I started in the refrigeration industri in Denmark.

Mounting the TEV sensor after the heat exchanger was frequenly done when we made a custom built air handling unit with a large area evaporator.

It was actually recommended by the supplier of the evaporator and heat exchanger.

In this way the evaporator became smaller and cheaper because a smaller part of the evaporator was used for creating the necessary superheat signal.

It worked and the suction gas superheat corrosponded to the compressor manufactures requirement for R-22.

The next time I was involved in mounting the TEV sensor after the heat exchanger was in connection with the first Danfoss electronic controlled expansion valve type TQ-PHTQ around 1985 on chillers with shell and tube evaporators.

Mounting the TEV sensor after the heat exchanger gave normally a much more stable sensor signal, especially at low load conditions.

The reason for this is the shell and tube evaporator, where we can have superheated gas in the top pipes and non superheated gas or even small amounts of liquid at the bottom pipes.

In such a situation the TEV sensor will sence a signal which is a mixture of what happens from the top to the bottom pipes.

So in this case it was also advantageous to mount the TEV sensor after the heat exchanger.

The conclusion must be:
As usual in refrigeration and air conditioning the truth is normally not either black or white, but can be anything in between.
It depends upon the hardware, the load conditions, the refrigerant, the TEV sensor signal at various loads, and ....

Normally the TEV sensor is not mounted after the heat exchanger, but there can be refrigeration systems where the mounting of the TEV sensor after the heat exchanger can/will improve the system stability and performance.