There are dual 18650 mods in use and working with the balance charger. The firmware update that supports it is available and a wiring schematic has been posted to use the balance charger. What evolv will be releasing is a add-on chip that prevents reverse battery installation errors/damage. If you are sane with your battery install, then you can have one today.
I know I have 2 that I made with dual 18650. I'm referring to the cloud maker dual 18650 option.