Properties of Joined and Unioned Objects

By experimenting I can’t understand what determines the dominance of properties when objects with different properties are united. Thoughts welcome.

Hello - with post-select the first object selected wins, with pre-select, the order is determined by the order of objects in the database - invisible, of course to users - most recent wins. To force an object to the top of the pile, Cut/Paste it.

-Pascal

Thanks P