I've never heard of Lipo or Life batteries puffing due to storage at high voltage. Puffing is usually the result of hard use.

The "problem" with storing lithium batteries for longer periods of time is the effect that the voltage they are stored at, impacts their capacity. The higher the voltage, the bigger the impact. But you don't want to store them too low or the voltage might drop too low during storage and ruin them.

I use a Life battery and don't worry about it. If after 4 or 5 years it's not usable anymore, I'll just buy another since they aren't that expensive. Also I like the fact that I don't have to worry about self discharge.