Suggested Extrude Surface Tool Improvement

Sorry Steve, I wasn't making myself clear.

We often create a set of master sketches to drive a form. These sketches will have multiple splines/lines etc. Below is a very typical example.

What we often need to do is generate helper surfaces for Boundary/Loft/Fill etc, and we use the extrude surface (often with draft) for this.

In this scenario, Extrude Surface does not let you pick the individual splines or elements (or groups of splines etc) contained in a sketch - rather, it just selects the entire sketch - as below.

In your example the splines are not continuous - but linked by a construction. In that scenario Extrude allows picking of individual elements. Like below:

But if you go back and edit that sketch and turn off the construction spline so you get a contiuous form, two things happen. If you try to add extra splines to the extrude, it selects the entire sketch. It does also not allow you to select additional splines as contours. So clearly there is no technical reason why SolidWorks cannout allow selection of sketch elements - it just does not allow you to - hence the reason for the request to open up Selection Manager to all geometry creation tools - then we can pick what we want, reduce the number of sketches we require, and simplify things.