I usually only vape in TC and with the temp so low, it could be hitting the ceiling backing down the power equaling a softer hit. I just got my DNA board and it's not in an enclosure yet but my yihi chips I set 50-60joules / watts at ~400-450F
I like the dual 18650, I was going to buy a kit on ebay that has all the cut outs but I wanted to do parallel batteries. now I see it can be done. awesome.