There's some very uninformed opinions around regrding auto's.
My findings showed that best quality of smoke and tightest buds came with 12/12. Worst looking plants with most popcorn and weakest smoke was 24/0. Joint Doctor himself says they can be grown anywhere from 12 to 24 hour light cycle but he recommends 18.
For me, the extra 5 - 10% with 18 hours light was around 2 - 3 grammes and cost 6 hours of electic per day for 8 weeks, which made it an expensive 2g.
If you remember though, one of the reasons you are on 12/12 is because the Blueryders are not a stabilised strain so you don't know for sure if you have auto's or not and 12/12 guaranteed that the bagseed and all the Blues would actually flower.