it's a bit rough and ready with no error checking evaluate the attached macro script and add to your ui then in editable poly select an edge and press the button and you can slide along the edge all you want.... it could also be adapted to work on editable mesh
Yeah, I guessed it after Klunk's script. Also works with tape helper . You snap it to edge vertexes and then can "pick" aligned transform gizmo. Still in Blender you can select multiple vertexes or an edge loop and move it outside along each vertex adjacent edge direction .