@cigatron re: your Q about cutoff,
I happen to notice it was set to 2.8V (OOB) as I poked around the Mod Tab. Prolly wise to raise that number to 3.2V
Vaped the Drone down below 20% and exchanged the batts with fully charged. The used batteries showed around 3.5V on my charger. That means you can likely vape down to, or near, 0% battery/charge without danger. Though, to repeat, you would best raise the cutoff from the stock 2.8V.
A far cry from LiPo usage. I discarded a LiPo today that would not initialized a Halcyon. My external charger showed 0.0V, 0.0V, 1.58V. Not good!