That doesn't tell me anything about how it works. Everyone can see your expertise but the way you are conveying it is over most of our heads. Do you have a simple line drawing showing the system?
John, my "lol" was in reference to how many models are listed there, which I would conclude they use about the same system for about any cab.
I don't have a schematic of the system in question in this thread, but I know how they work.
The valve in that picture is a TXV/Hvalve/Hblock/metering device. The little disc on one end is called the "power head" that has a proprietary gas in it that will respond to suction like temps. On a stationary system, that 'hat' is usually connected to a tiny copper tube and "bulb" to sense the suction line temp.
You will also see down one of the barrels there is the needle valve. There is a spring on that needle as well, that works in balance with the power head. It is 100% based on suction line temp. There is no way to control those any other way, and usually not even field adjustable, which limits some level of diagnostic in them.
The TXV was ultimately designed to try to maintain "constant superheat". In a fixed orifice system, superheat will be all over the map, and largely underfeed the evaporator in a hot pulldown, thus high superheat. What needed to happen was the ability for a hot system to 'open up', allowing more refrigerant. However, if you run at full bore once things are cooled off, superheat drops to dangerous levels that risk liquid returning to the compressor. This is where the TXV would throttle down, limiting refrigerant to the evap, ensuring it all boils off and leaves with the proper amount of superheat. A ballpark is about 10* of superheat.
But in any system, a TXV cannot fully shut off refrigerant flow as the compressor is still running. This is where temp and pressure switches come into play and if the suction line gets to a low point, it will cycle the compressor off. Due to the liquid receiver, refrigerant will still continue to flow, but at reduced pressure and thus the suction line temp will increase. This will then tell the AC control to kick the compressor back on.
there are also low pressure cutouts on the suction which were common for orifice systems, but they still play a role in TXV because if that pressure is too low, that could mean low refrigerant charge, which could damage a compressor.
Not sure if any of that helps in the clarity?
https://www.mechanicalbooster.com/2017/12/car-air-conditioning-system.html
Here is a link I found with a decent a simplified picture of how the TXV connects. What is unique about the mobile TXV device is the integrated sensing bulb that is reading the temperature of the suction line going back to the compressor. There are no outside controls for that device unless it is an EEV, which is not common for these.