I work a lot with STEP assemblies that get imported with parts and a layout sketch contained in a part. I am trying to figure out an easy way to fix the 3D sketch so that I don't accidentally modify it.

I have tried select all then adding a fix relation, but then all of the line end points are still free to move in space. Unfortunately it looks like fully define sketch is not available for 3d sketches. I also tried using a selection filter for only sketch points, but this won't allow me to select these endpoints. I can successfully click on a single point and fix it, but the number of points in these sketches makes that a non-viable solution.

Any thoughts?