Only thing I will be honest that I don't like is I don't stack batteries and for this one you have to stack 18350's for it to work.
The regulator used for the VVG has as many built in safety features as it can have. There has never been a single "stacked batteries" incident reported in any device using this regulator... and this regulator isn't exclusive to the VVG. It comes from the very first and longest running (still made) commercially available VV e-cig. There are thousands of PVs out there with this regulator.
I don't know if that will make you feel any better or not, but it is a fact.
As a side note, the design of the VVG doesn't lend itself to pressure building up inside the unit even if there was an incident (which there hasn't been). That squonk hole will never let a REO turn in to a pipe bomb or allow pressure to build and blow the connector out the top. The injury incidents talked about on ECF happened with improperly vented devices that allowed pressure to build inside. They were unfortunate, but both occurred in devices without protective electronic features and without proper means of venting expanding gasses. The community has taken note of those shortcomings and manufacturers and modders have taken steps to ensure safer devices.
