I've been doing that constantly to be honest, i admit a couple of months back I managed to think up a whole new mini chapter due to it, and all based around 1 person, I was quite impressed, as was those few I've let read what i've got so far, but my on/off breaks have gone on for too long now, I just look at what i got and get annoyed as I know if I go back to the publisher with it now, they'll say the same again "either cut it down to go in a collection novel or work it up to a full novel"
