Always better safe than sorry with kids....and I agree most "puffed" lipos have been damaged by over charged, discharged too low or have been used in an improper application (too high of a current draw for the pack)

I do not overcharge my packs....I use a storage charge during the off season or when I am not racing for a few weeks.... I have lipo cut off on all my Esc's....... very very rarely do my packs get ran long enough to get anywhere near the low voltage cut off. I balance charge my lipos every time, many peope think that's ridiculous and only balance once a month or something like that....I balance EVERY charge and if I cant get a pack balance charged between races I switch packs.... I can be a little anal with certain things and after all that my soft packs still have a slight "rounding" usually I notice it developing after using them regularly for several months.

I think all lipos with age & use will develop some slight "rounding"....I am talking a mm or two at most.....I feel they are safe to use...they balance well and quickly on evey charge, they take the right mah compared to newer packs....no sign of an issue at all. I have had packs "puff" more than I feel comfortable with and they have typically shown it by taking longer than normal to balance and when I plug it in the charger shows that one cell's voltage is off verses the others.....These were the packs I usually used for bashing in a monster truck...ran in snow, water, heavy loads for long periods of time....and they were replaced immediately

I have soft packs that are over a year old... and some are well over 2 years old, I just dont use them regularly any more after switching to hard case in everything.......but many of them have slightly "rounded" over time....It's much easier to see the "rounding" on a soft pack......I would not say they are "puffed" but they are no longer perfectly flat.

I have seen people use lipo I would call extremely "puffed" they are very noticeable rounded and barely stay on a pit table without rolling away No way would I put one of those in my vehicles.

One thing I have noticed on hard packs.....I have opened several hard packs that have room between the cells and the case, so they could swell several mm and not even touch the harcase, so there is no way to see if they are starting to "puff" or not until its pretty noticeable.....I have opened others that the cells literally press tightly againt the case and you could barely get the case on....so even a very slight "rounding" of the cell shows on the case....also some hard cases are much thicker and stronger which would be less likely to show the "rounding" as early

So I have a hard time using the appearance of a cell as the only factor in judging its condition.....I watch the individual cell voltage, charge time, balance time, mah input etc..

Long story short.... if you have any doubts get rid of it....but to say "any puffing at all" means its bad is pretty vague and leaves way too much room to personal interpretation.