Geopak Site - Extend slope

Not directly.

Do you have a typical design scenario where this is used or would be used?

For instance, assume the top of bank of a stream is to be raised and the slope is to be the same as the existing bottom of bank to top of bank (which varies along the stream).

There is a method to do this now... its not exactly "automatic", but will achieve the result.

Use the New/Edit>Slope from Element tool.

Set the slope option to "Variable".

Populate the table with slope values that replicate (within reason) the slopes that are already out there... Use the Height Tool in Slope mode to analyse the existing slope conditions.

That should get you the result you are looking for.