Direction of wind seems optimal / lucky, saving the too-close adjacent module (seen on the left on the latest photo on this thread). I agree a few extra meters would be insignificant regarding land cost, but oh well, it haven't spread so maybe it's good enough as it is.
Regarding toxicity of smoke, remember, "normal" smoke is rather toxic. Even when just burning wood or fuels that are supposed to be burned, even in optimal burning conditions, exposure to smoke must be still very limited. Burn plastics at temperatures too low, and it's already orders of magnitude worse. Likely the contribution of the electrolyte is small because the amount of electrolyte is small compared to everything else burning.
Any large fire causes people to be evacuated down wind.