I think more than just efest
batteries get rewrapped. But I feel ya.
It might take a newbie wrapping a .15 ohm coil (beginner's luck? chance?) using an efest to vent a cell, or at least make it really hot, especially if it's in a mech. But how many newbies do you know who go about wrapping a .15 ohm coil right off the bat? If it's one of their buddies who hands it off and something goes bad, is it the battery's fault or the user's?
Hopefully in this day and age of regulated
devices (even regulated devices don't provide 100% safety), this shouldn't be too much of an issue. A year ago, yeah, with mechs, maybe.
Blame the Chinese company all you want, I doubt it'll make any difference. Sort of like guns, though. Know what you're doing and using and you can have one hell of a fun time. Don't know what you're handling or don't respect it, if you blow you're own head off... is it the bullet's fault or the person holding the gun?