How about the simple approach?
Make a "glove" for it.
Imagine a rubber cylinder that you snug your GG into, so only the atomizer sticks out, - - the button will be able to be pressed
through this rubber if its the very soft kind, and the rubber itself will keep the GG from self-activating when in contact with metal?
It will also help the GG look like a GG - and you could get a GG logo on it?