Reciprocity failure is about the lack of photons. If you don't supply enough photons, you don't form a latent image. If you don't form a latent image, you don't have anything to develop. Therefore changing development time is a moot point.
Originally Posted by njkphoto
I think you'll find that no matter how you develop the film, you have empty shadow areas. This will be true because you didn't give enough exposure for the shadows.
Depending on the image and your intent for it, this might not matter.
If you want better reciprocity characteristics, consider using a more modern film, Acros, Delta, Tmax come to mind.