Edge Zip

Use the Edge Zip tool to create new SubD topology. An edge selection is welded to the corresponding edges running parallel to the original edge to create new topology.

Before

1.   Add a Sphere.
2.   Activate the Edge selection mode and double-click on an diagonal edge to select all of the edges in that loop.
3.   On the left panel, under the Mesh Edits tab, click Edge Zip.

The edge has been deleted and the mesh adapts to the update.