Like Dlovell... I've never had a Kayfun flood when built with a proper wick. I won't go into the variations of wick materials and designs that work, as that could take up several paragraphs. As Dlovell suggested, read several of the threads on Kayfun and their clones available to you.
Extreme temperature changes, with the associated expansion and contraction of metal/plastic,
could cause minor leaks with an atomizer that has borderline sealing qualities to begin with... but pressure (extreme elevation) changes would be the most likely (external) source for any sort of flooding.
That potential exists for any
pressure differential atomizer... and easily avoided by simply revitalizing/maintaining the vacuum as those elevation changes occur.