I think the only wrong way is to not use the stuff you talent into.IE pick up cold snap and then act like its not there on H-Ultra. and then only take 1 HoT.
Unless you kill him before needing the second ice block? :P(Let us remember, the dubuff that will still kill you is still present, unless I just somehow missed that in the patch notes)
Ya there's a 2min debuff from HoTYou'd have to kill him before HoT4 then.and its really just an example.