Checking in at 3+ weeks, hopping along nicely.
Regarding the blue lights, here's what I notice with mine:
The dial/clicker piece on mine has a little bit of give side to side, independent from the lower thread part of the back end. Very little, like just a fraction of a mm, but you can feel it shift when you press it with your thumb to one side or the other.
When shifted to one side the blue lights blink, when shifted the other way they stay perfectly solid.
I have repeated these results with batteries at various stages of depletion.
It works either way, using it many times daily.
Here is some video demonstrating my observation.
https://vid.me/t1yV
While fiddling with the back end for extended periods of time, I have two or three times managed to turn the unit on without depressing the button, or once or twice with a half click. That, combined with the orientation changing the lights from flickering to solid, leads me to believe that there is a slight imperfection in the machining of my back end, causing it to not make a perfect connection.
I will say that it continues to work consistently in spite of these quirks, and man it works so good. I'm a fan boy by now for sure. Even with the imperfection I will also say it feels very sturdy physically, not "janky" like it is going to break or anything. Whether or not the electrical will hold up is anyone's guess though. When I get my pre-order I will see how they compare.