I find that Segment Editor’s Margin effect does not achieve the same job as Editor’s “Four Neighbor” erode effect. What resources would be useful to implement a tool where the user selects neighbor type and erode/dilate then apply it to the segment?
Segment editor’s Margin effect uses a sphere shaped structuring element, which allows adding/removing margin by a specific size (regardless of pixel size and segment surface normal direction).
For noise removal, I would suggest to use methods available in Smoothing effect.
The legacy Editor’s 4/8-neighbor erode/dilate effect was very limited (mostly usable only for removing very small amount of random noise), as it grew diamond-shaped regions, with shape depending on the volume spacing.