I haven't read
through every post here, so if it's already been clarified, I apologise.
The fault with the DSE905 V3 appears to caused by the cut-out. Once the cut-out is triggered, the body (including the atomizer/drip tip) carries 3.7v - not enough to notice to via your hand, but enough to deliver a buzz through wet lips on a drip tip. Of course, if you're using carts, you won't notice it.
I've tested three DSE905s (from different suppliers). I've also had a few friends replicate the test on their as well. All had / reported the same result. I have no idea if this is a batch thing, or is a design flaw affecting them all.
As for the OP's comments on the poor
vape on the 905 - if you've got an atty running 3.3ohm (mine are all 3.0-3.2ohm), the most wattage you're going to get with stock
batteries is around 4w. No where near the target 8-10w most seem to aim for. There is a crowd in Australia (
Vaporosity) who sell modded bottom bodies for 6volt (2 x CR2s available from DX) which will give you much higher wattages and significantly improve the vape.