The documentation for SafeLayout uses the Edges property on the SafeEdgePanel:
<SafeEdgePanel Edges="LeftTopRight" Dock="Top" Color="#FFF" ExtraPadding="2">
Trying to use this creates an error Error : 'SafeEdgePanel' does not have a property called 'Edges'.
Looking at the SafeEdgePanel documentation the correct property name seems to be PadEdges.