M.G. said
"History updates are not enabled by default for all the Transform commands. I'm a little bit worried about automatically turning on history all over the place, since it can sometimes lead to unexpected results if you wanted to edit the newly created objects as independent objects. Maybe mirror should be an exception though."

That's why you should think of adding a choise when copying, mirroring etc.
This choise should be INSTANCE or NEW
Instance: History update is on, no matter which command you choose
New : A copy or a mirroring of the initial object, a completely new object.
A instance->new transformation would be very nice to have too.

Just some ideas for V2.0