I was wondering if this is possible because not all properties that are exposed through the Json API when fetching hardware/devices are related to properties that affect the display values but would still be useful to be able to dynamically change in a 3rd party app that communicates with the ...

To my knowledge I don't think the web interface provides a way to change the individual properties of a device. So does that mean there is not a way to do it with the Json API?

Is it possible to update a particular property on a device (such as a Wind Sensor's Wind Speed property) using the Json API?

I'm aware that this command will update all values for a Wind Sensor:

/json.htm?type=command&param=udevice&idx=IDX&nvalue=0&svalue=WB;WD;WS;WG;22;24

Is it possible to ...