Grid does not fire needLoadMoreData until user stops scrolling or until scroll reaches the bottom of the grid

$scope.gridOptions = { infiniteScrollRowsFromEnd: 100 }

It seems as though until a user stops scrolling the "needLoadMoreData" event/function does not get called and is not accounting for the infiniteScrollRowsFromEnd.
The idea behind infinite scrolling is that you can start the request for more data before the user reaches the end of the grid and it would be awesome if the grid would start the request even if the user is still scrolling and would subsequently concat the response data to the end without messing up the scroll position (even though I am using saveScrollPercentage).