Look. I have a Dripbox. I actually love my Dripbox, which is odd for a Kanger product, but what can I say? The price was too good to resist.
It's supposed to be a regulated, protected mod. It's supposed to have low resistance protection. You aren't supposed to be able to fire it under .2 ohms. Here's the thing, if you're stacking another coil on top of the two already in the pre-built deck, you're probably firing under .2 ohms (unless you have some uneven resistance shenanigans going on, and you don't wanna do that either). This confirms my suspicions that you shouldn't trust a Kanger chip as far as you can throw it.
I'm not going to tell you not to use your Dripbox. I use mine. But for the love of god stop this foolishness. I treat my Dripbox a lot like a mech. Always test your coils. ALWAYS stay within safe amp range for your battery. Due to some concerning reports of a couple catching fire, I always unscrew that adjustable piece on the battery door, so the battery doesn't make a connection when I'm not using it. I don't even use the stock coils. I'm not comfortable with the safety implications of a .2 ohm build. Plus....my coils are better anyway.