That's interesting, thanks. I just tested my initial script (see top of thread) with my "'No Actor' selected" use-case.

First use: the script switched from 'No Actor' to select the one prop in the scene, as expected.

Second use: the prop stays selected (or, is re-selected, after the slightest flicker).

Third use: I delete the prop. 'Main Camera' is then auto-selected by Poser. I run the script, and GROUND is selected.

So yes, it seems GROUND is indeed a prop.

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