On dual coils, especially when using twisted wire, I like them to be 0.9 ohms or less for quick heat up time. But then my single coils are dual coils, since I am using twisted wire. But yeah, tis the beauty of devices like the DNA30, don't have to worry about the ohms of the build, just crank the watts and no worries. I'm vaping 23-30 watts on both my Rose2's. Once you get your dual's set up, just crank it up to where you like it. You should be fine a 1 ohm with duals. Sure you will find your desired range. The other reason I like under .9 is then can vape with any of my mods, mech or regulated, and get a damn fine vape.
On an after note, now that I've had the same builds for a few days, the Ramie fiber is totally saturated and jc has settled down nicely, leave both open about one full turn when vaping at 23 watts, no gurgle, no dry hits, if I crank it up some more, just need to open it up a hair more to supply more juice. Really working Sweet. Broke it down after a few tanks and wick still looking nice and white. Yeah still in a state of Rose2 euphoria.