Try using some shrink tubing behind the USB cable connectors for reinforcement...done that for the last 10 years without issue, and cable breakage.
If you want something with a ridiculous amount of e-liquid capacity, check out an aromamizer plus. 20ml tank, you can throw some massive builds in there that do not require 500w to fire, and they have loads of airflow. (they are on the large side, so you'd need something like an rx200s to handle it, which also has the added benefit of triple 18650 batteries...longer vape time between charges)
*One of my brothers from another mother works for NEMF, and he's constantly on the road for hundreds of miles at a time, and I set him up with the same set-up and it's all he uses.