The strange case of the blur borders effect
I was forced to upgrade my older Macbook Pro, and thus move my presentations to the newest Keynote (7.0.5) from my older 2009 version of the software. I have grudgingly come to terms with the lost features, such as restrictions on video formats, missing transitions (Falling Tiles, Burn, etc.) and so forth, but one feature has me puzzled. I sometimes liked to blur the edges of images and video clips using the Borders "Picture Frame" selection that softened edges; it had a slider that allowed you to adjust the degree of feathering. It is seemingly missing among the Picture Frame border options in the new Keynote; however, any of my old presentations that included that effect still have it, adjustable sliders and all.
Stranger still, I can copy and paste the style of an older blurred image and paste it to an image in a new presentation... and the blurred edges are transferred to the new image, and are adjustable. So apparently at some level this is still "allowed"
MacBook Pro with Retina display, macOS Sierra (10.12.2), 16 GB