In the latest version of PanX and the latest public beta of maxOS, a text display object that contains the text display function is immune to any attempt to adjust its opacity, by both the opacity slider or the changeobject command… the blueprint and the slider may say otherwise but the opacity is always set to 100% if the text display object contains a text display function.
I can’t vouch for the latest public beta of macOS Mojave, but it works on the latest version of Panorama.
I know Apple has made some major changes to the way View layering is implemented in Mojave, I hope they get this sorted before Mojave is released.
Wait, that’s probably the problem. The color specified by the textdisplay( function will override the object color. Opacity is a component of the color, and the color specified by the textdisplay( function is always fully opaque.