i would not recommend using an RBA on any type of ego.
even if you build a coil with the proper resitance, that doesnt mean it will stay there. if your RBA skills are top-notch you may be okay, but im new at building coils and i have noticed that your coil can fluctuate resistance out of nowhere. if its not wrapped properly (or if your wick is not properly oxidized, or if the wick hits the bottom of the tank) you can get a short and blow the battery.
ive never had a vivi nova head short after being rebuilt properly, but i just got a Vulcan (DID Clone / CHID) yesterday and ive gotten the OP error code so many times i cant even keep track. its weird, it will go from 2.5ohms, up to 6.6ohms, then down to 1.6ohms, then OP for example. this is all without touching anything, just
vaping it. OP is open current and if you get an open current on your ego, kiss it goodbye.