Strokes should never be committed to the gray portion of the canvas, unless they're part of a Scrap (or Temp Scrap). This means that the way they work now is ok for strokes that are drawn to the outside of the drawing area (even partially), but not for strokes that are moved to the gray area using a temp scrap, and dropped there. When they get dropped, they should be deleted.
Strokes should never be committed to the gray portion of the canvas, unless they're part of a Scrap (or Temp Scrap). This means that the way they work now is ok for strokes that are drawn to the outside of the drawing area (even partially), but not for strokes that are moved to the gray area using a temp scrap, and dropped there. When they get dropped, they should be deleted.