Is there a technique to select border edges only?
If it’s a loop you can double click one edge to select the loop. Selecting an edge, then shift selecting another edge with a double click will select all edges in between. Also, you can select the polys the edges define and shift/s to select the edges (you will have to delete some edges from the selection if there is more than one poly).
Try Select Special Geometry filtered by Edges with Faces=1
YES! Select Special Geometry filtered by Edges with Faces=1