Generally true. I avoid most dual coils on eGos. If you have Joye eGo batts, they do well on
Joye eGo 1.5Ω 510 and 306 attys and the eGo mega attys for some reason, but other 1.5 Ω or below, you're on your own

... based on my experience.
You can also get into trouble if by gunk on the coil, etc., where a 1.8 ohm coil drops below say 1.5 ohms. The three flashes of the button led indicates a short. With the eGo-c and eGo-c upgrade batts, you get one more short before they die, because of the upgraded short protection in those type batts. With the other joye eGos and cloned eGos, you'll likely have a dead batt.