How about constructing a gizmo with piece of plywood (small) and have paperclip hanger from 4 corners that will attach to the sporacket holes of film? After developing, guestimate half way point, hook two hangers, go to the other side and hook two more. The film will form an up-side-down U with gizmo at the top. That way, you won't be cutting the film, won't be handling it too much, and two side hanging from fold will be kept away from each other by the width of the plywood.