Which dangers? Just curious.
One is so common, it's got a nickname: hot pocket! Button gets accidentally pushed while in a pocket or it jams down and the user doesn't notice. In either case, it keeps heating. Some manuals have circuits to cut it off after a certain number of seconds, but not all do, and the circuits aren't foolproof.
Most of the batteries which explode during recharging are manuals. I don't know if it's a case of less control circuitry or a tendency for buttons to get pressed down when put into some chargers, but 11 out of the 12 exploding batteries I've read about were manuals.
Steam explosion. It's been known to happen that a bubble of steam gets trapped on the coil by a glob of juice. When it finally breaks free, it shoots the superheated juice out the mouthpiece. A year or so ago, someone on this forum posted a YouTube video of when it happened to them. The difference is that with automatics, the worst it can do is put a blister on the back of your throat. In the posted video, because it was a manual, they had pushed the button before putting the pv in their mouth, and the juice hit them in the face. It's only a matter of time before someone gets hit in the eye. I've heard of six other such incidents in the last two years.
There are other dangers, but you get the idea.
They're always isolated incidents, and when you consider the number of vapers and the amount of hours spent vaping, they're really rare, but they do happen, and they happen to manuals rather than automatics.
I also live under a cloud -- if anything can break in a spectacular way, it'll happen to me (the very first new car I bought, I was less than three miles from the dealership when the bell housing broke; a new motor for my table saw came apart, flinging a plate against the underside of the table hard enough to crack it (which is when I learned about warranties not covering incidental damage); a new car battery it exploded, spraying the inside of the engine compartment with acid; my first VHS VCR caught fire for no apparent reason; etc. etc. etc.).
The only danger I've heard about automatics is that some of the cheap, early ones used a microphone instead of an air pressure switch, and they could turn on while in a pocket, but that's been corrected so long ago that I doubt that any of those batteries are still around.
