I wasn't going to waste any more time here, but wowthisisrmdoms comments about the digital display brought this website- Vaporizer Notes - to mind. I will share it anyway for other readers who are genuinely enquiring about this issue. It's worth a look as it deconstructs a cheap simple vape and in the course of doing so reveals the ugly innards and discovers only 9 step settings for the heater- not the incremental degree precision that the digital display would have the user believe. Designs might have changed since, but as a case study example I think it's quite informative. Short excerpt, note the warning; Heaps more useful info if you follow the link.