I've tried twice today to write a response to these suggestions but I don't think that I managed to get it posted. The "Add Comment" button, which I'll try now, has been hidden by Renderosity's notice about cookies. I checked the Materials page for the Flink skydome that I've used. Ambient is set to White and the skydome disappears if I set it to Black. That's not causing a problem for me. In fact, I'm glad that it works that way. I'd just been wondering why a skydome prrop can be seen when the scene's lights are all OFF. Now I know. Thanks to you all for helping! 

Thanks for the info. However, this is probably a bit above my level of competence. I'd better just stick to doing it the hard way.

Thanks to everyone who had suggestions. I guess there is no way to do it "the easy way," so I'll continue to move my smart props manually to the origin and then re-parent them to the Universe, check the "Inherit bends of parent", and exit to set the props' coordinates to the world origin. The prop can then be saved to the Library and it will load at any new scene's Origin.

Thanks for the suggestion. When I say "find the prop", I don't mean finding it's name in the Props list. I mean finding it in the scene so that I can click and drag it. When a smart prop originates in a very large scene, it may be located way out of sight. Sometimes the only way to find it is to switch to the Top Camera and move it way up to show more scene. Enlarging the Scale can also make it easier to see. But these sort of things are what I was hoping to avoid by "un-smarting" the smart prop: I would like to select it from the Props list (as you suggest), "un-smart" it so that is coordinates can be reset to the Origin of the scene (0,0,0), the prop is then moved by Poser to the Origin. Then I can move it to wherever I'd like it to be. So far, none of the suggestions allow me to do that.

Thanks for the suggestion. I've downloaded the script and can try it. However, this still means that I must find the prop. A smart prop from a large scene may be difficult to find. Of course, I could scale up large enough to see temporarily.

Thanks for the suggestion. When I do that, the dial readings change and the prop now moves to a new "0,0,0" position - but that's not to the actual origin of the scene (where Michael_4, for instance) loads to.

Thanks for the suggestion. That is pretty much what I am doing now. But that technique requires me to find the prop first (not always easy when the original scene is large), then manually move it to the origin. I've been hoping there would be a way to just load it, un-smart it, reset it's coordinates to 0.0.0 and have it appear at the scene origin.