From this Forum Post https://www.noesisengine.com/forums/viewtopic.php?t=4034 , there was an interesting suggestion to bring in the 'Spacing' Property that was added to the StackPanel, and also have a similar one be available on the Grid Element.

There may be some considerations for implementing this into the Grid Element itself, but as far as the UniformGrid Element, there is a good argument for adding this Property as the UniformGrid in a lot of ways is a 2-axis StackPanel, in how it populates its 'children' dynamically; and adding a 'Spacing' Property to it that just like the StackPanel, only impacts internal spacing (and not external 'margins') would be a useful addition to superpower this Element type further.