Thats a tough question to answer without knowing all the details about the plants ancestry. There is no way to know if any environmental factors may have affected the parents in some way to cause your plant to not flower. IMO, I would probably go to 12/12 for two reasons, 1: you know 12/12 will induce flowering. 2: it will save money on electric bill.
Even though Ruderalis has been around for a while, there still isnt enough research to conclude that they are stable for breeding. I would use caution with those auto flowers. Personally, I think they are just slightly better than a hermie..lol