Here is the response from iToo:
Yes, that’s the expected behavior in this case - these items are being randomized by the Transform settings, which can slightly affect the overall shape. To achieve a sharper edge, you may reduce or disable the Transform > Scale parameters.
Just to clarify, the Edge Boundary Checking mode is not intended to 'slice' geometry. Instead, it removes entire elements within a single item if they are positioned outside the distribution area. So, if any part of an item — such as an overhanging face — extends beyond the boundary, it will either be fully included or completely removed, depending on whether its base is inside or outside the distribution area. This method also helps maintain performance, as slicing geometry would require significantly more computational resources.
