SINGLE 18650 MOD safe to USB charge? & What battery for these MODs?

I've read the reason you shouldn't charge via USB is because multiple (not single) batteries can be a problem for cheap chips (or anything besides the DNA basically). When we only had ego Twists and stuff with a single internal battery, everyone USB charged and passthrough vaped with no worry. Or people just used an external because it was quicker.

Anyway for some reason I hate removing batteries and charging in an external, so I spend the extra $100 or whatever for DNA mods only after…

<a href="http://vapingunderground.com/threads/single-18650-mod-safe-to-usb-charge-what-battery-for-these-mods.381595/”>SINGLE 18650 mod safe to USB charge? & What battery for these mods?