A diverted train is only of limited value to passengers between Wigan and Bolton. It is of negative value to passengers at Preston, Wigan NW, Manchester Victoria etc as trains are out of place and have to work with the diverts. You are more aware than most that the railway must look to all it's passengers and customers, not just those on one line. The best option to me would seem to be ticket acceptance on alternative trains via Preston or Eccles for the duration of a blockade, so that passengers are not financially impacted by the longer route.