You will be absolutely fine with a .7 build with those batteries, I own two of them and I have routinely used them in builds as low as .45 ohms and I have not once had a single issue with them, they haven't even gotten a little warm during use even during long 7-8 second lung inhales and chain vaping. My only complaint with them is the short battery life, but they do charge back up from 3.5v very fast.