HCP? Been around here a while and never seen that... I'm sure it has something to do with parallel coils, but not quite sure.
As to the Nuppin' heating up, I have been vaping both mine with .20-.25Ω dual setups with 26g Ni80 wire and have no problems with heat. I haven't used a drip tip on mine in several months now. Every now and then I might have my lip a little to far over the 510 hole and the vapor might come out a little warm, but never had a top cap heat up where I couldn't vape it... I pretty much chain vape all day as well.
As to the Nuppin' heating up, I have been vaping both mine with .20-.25Ω dual setups with 26g Ni80 wire and have no problems with heat. I haven't used a drip tip on mine in several months now. Every now and then I might have my lip a little to far over the 510 hole and the vapor might come out a little warm, but never had a top cap heat up where I couldn't vape it... I pretty much chain vape all day as well.