@Jean Lemire: very instructive!
I function as a tester for Tgi3D so I find all sorts of strange Sketchup bugs. A few months ago I came across a SketchUp feature which could be considered a bug. Imagine you are performing a move rotate or scale operation inside a component instance, Sketchup inference engine allows you to snap on a feature in another instance of the same component (which potentially depends on the edit you are performing). You can have Sketchup solve equations for you (or draw a dodecohedron directly for that matter).
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