Combine surfaces boundary

I was looking at the combine surfaces tool and was wondering if members could be add outside of created “islands” or if the boundaries that bound those islands can be altered?

Sure - the combined surface is just a surface model with boundaries added around the islands - if you add data outside of the boundaries to the surface, you would either have to

  • Remove the boundaries that have been applied to the surface or
  • Add an extra boundary around the additional data that you add so that the surface can be extended to include the new data
  • Edit one of the existing boundaries to include the additional data

The combined surface is just a surface like any surface - you can add / remove surface members, add surface boundaries etc.