The Topography API currently provides a wealth of options for creating and manipulating Topo's. One important method missing (that is part of the UI) is Split Surface.
It would be great if you can provide a method to Split a Topo Surface. Something like:
TopographySurface.Create(document, curveLoops, sourceTopoSurfaceId)
A similar method already exists for creating Sub Regions:
SiteSubRegion.Create(document, curveLoops, hostTopoSurfaceId)