Really doesn't seem worth the drawbacks.
I agree, but others are willing to put up with the limitations and inconveniences for a portable, pocket-friendly mod.
I understand the draw towards a small mod. One of my first mods a few years ago was a mechanical AltSmoke BB. It used a 14500 ICR or IMR battery, which has the same dimensions as a AA battery. It was perfect for short trips to the store or for an afternoon when out and about. I was using 2.0 ohm cartomizers in cartotanks on the BB, so they weren't much of a drain on the 14500. However, I found that I had to always carry one or two spare batteries with me in case I was out longer than expected. My vaping application changed over the years from a high ohm/low wattage vaper to a sub-ohm/high wattage vaper, so my BB has been sitting in a drawer for a few years. (Currently out of production)
BB
I also have a Provari Mini 2.5 which can use an 18350 battery. Like the BB, it was great for out and about trips in the car, but necessitated bringing a couple of spare batteries to last out the day. Not used much today because of its low power output.
Provari Mini