my research showed that these IMR are safer than any other battery including alkalines that we see stacked in boom box radios. I am weary, but only if when I see them get too hot. Temperature, to me is the key to safety..
Besides, if I could learn to build a coil that vapes the same using 4 volts I would, but at such a low ohm as I see some folks cloud chasing, I'd be likely even more weary. I call what I got going half a cloud, which for me is plenty and way more than I can get from anything I bought ie SVD, evic and countless ego batteries. The evic goes to 5 volts max, the SVD goes to 6. Each has its own Ohms laws going for them, that I cant figure out. The main reason for building this was to study the numbers, which I still dont have down yet.
I think by dc/dc module you mean a regulator chip with variable volts and such. That would mean using wires and a fire button. Again, my SVD allows stacked 350's and I just dont see the logic behind why that is any less safe. To me, it is a potential hazard using batteries no matter.. look at the electric cars that have burnt up.. none went boom, but still there have been a few that I am aware of.

This pic shows what I think some people are trying to do with a 30 amp battery.
I dont get out much but I would love to see how people are making such huge clouds.
See, I just dont understand coil resistance versus total resistance when it comes to those set ups.
With all that I know, it still seems to always come down to trial and error.
I COULDNT TELL YOU EXACTLY what I have going on hereas far as the numbers goes, but it vapes awesome.
Many have told me I think too much.. perhaps they are right.
With 4 volts 30 amps .13 Ohms 120 watts, would that be the reading at the coil or total resistance..
also wouldnt 120 watts be like vaping a volcano I wonder.. I have enough trouble keeping my cotton from burning at what I think is 25-35 watts. lol besides, too hot and I lose flavor..
I mix 3/4 VG to 1/4 water soluble flavor at 6 mg/ml nic.
These guys are doing all VG and at low to no nic so I am told..
Now I am not trying to compete with them, but it has always been my complaint of not enopugh air flow and not enough production.
With this build I solved this for me at least..
I looked at the white coffin box..lmao.. I wouldnt know how to set that up like I did mine, plus it is plastic.. I'd melt it soldering wires.
Again, I dont have any wires electronics or switches, its just solid 32in copper ground strap inside.
If I was to buy anything again it would be a DNA 30 mod to see what it can and cannot do. But it is not rocket science it is just about getting a good vape.