Currently it is difficult to modify geometry (origin, spacing, directions) of closed surface representation in segmentation nodes.
Geometry is set by default when first selecting a master volume in the Segment editor but later it is difficult to change using the GUI.

It should be possible to set the geometry by referring to a reference volume (optionally with over/undersampling/forced uniform sampling), or an ROI node (and spacing).

It would be useful to show the geometry to the user (maybe using a grid that shows spacing, orientation, extent).

It should also be possible to change the resolution of existing segments.

Also, add a GUI for rotating views to slice planes, as users are often puzzled about the paint artifacts and inability to interpolate between slices. (https://discourse.slicer.org/t/segmentation-error/1579, https://discourse.slicer.org/t/segmentation-editor-how-to-disable-painting-on-adjacent-slices/1459/4, etc.)