How to display a custom parameter value in the PCB footprint of my Altium component?
There is one way, some kind of workaround. But you have to give up the Component's comment field because we will use this to show a custom parameter on the PCB along with the footprint.




Add your new parameter and set it visible. Under Properties set the Default Comment to your custom parameter and do not check the Visible box.







Add your component to the schematic and set a value for the custom parameter.







In PCBdoc, right-click on the footprint and in Component Actions select Show Comment.







Now your custom parameter is visible under the footprint in the PCBdoc.