Repro Steps:

1) Create a Page
2) Create a uniquely-coloured 128x128 Border Element with a 32,32,32,32 Corner Radius.
Observe how the corners round as expected.
3) Apply a Vignette Effect to the Border Element, and make it a contrasting colour to that selected for the Border.
Observe how the edges of the Vignette effect are squared off, and do not follow the rounding of the Border in which it is contained.

Expected Results: Border Effects follow the shape of the Border in which they are contained.