[whpalmer4]

A stencil is only used at the time you create the object. The stencil object is copied, but from that point on there is nothing different about the object created — the stencil is just a shortcut for easier creation. Once the document is closed and reopened, there is no way of knowing if an object was created by hand or by stencil, and consequently no way to apply any subsequent changes to the stencil to the previously created objects. It's just like a drafting stencil — if you make a drawing with the stencil, then take a knife and modify the stencil, your drawing doesn't magically change to match the new stencil.