Hi Burr, I can certainly see how it was a kind of "what the heck?" type thing... :) But yes at the same time actually a good example of several of the mechanisms in MoI.

Probably the weirdest part was the cube kind of popping up.

History updates can sometimes make for surprising changes when you edit the original shapes. That's why they are not turned on universally for all operations, especially some more basic building block type commands like rotate and copy can lead to these kind of surprises when objects change when you edit the originals if you were not really thinking of the link between them.

But when it is not turned on then there can be a problem where it is not really that obvious to someone how to activate the link for doing things like adjusting a revolve by editing the original curve's control points.

So that's why in MoI history is enabled by default for just a certain set of commands, mostly surfacing commands like extrude and revolve.

- Michael