So I'm onto 34 hours of chain vaping, a good 33 I'd say are on the charger. Device still works, imagine that. I dont think low-wattage vaping, using the charger to maintain an already full battery, will cause any problems.
The usb charger isnt pulling the same amperage as I'm vaping it. Maybe it could if I hooked it up to an unregulated 5v source, but since my power source will only ever put out 1.5A, that's all it will charge at. The battery works as a shock absorber to the system, discharging on demand, and charging at a steady 1.5A. Maybe if I'm feeling bored at home, I'll see if it's even pulling a full 1.5A, or just 0.5A, or somewhere in between.
I looked through the materials that came with mine, and found nothing advising against vaping while charging.
I will say this, I would not advise charging and vaping at high wattage or with a significantly depleted battery. The mod gets warm when running at 50w repeatedly. It also gets warm when charging an 18650 at 4.0v. Making both things happen at the same time could overheat the chip, causing failure.
You may reserve the right to "I told you so" if it does fail over the next couple weeks, but I wouldnt hold my breath.