A singe currency is as feasible as world peace.
China, Russia, the UK, the US, North Korea or Japan will never accept a currency out of their direct control.
Readers don't read, or lack reading comprehension.
Why don't you try again to read the thread. The national currencies will float against the reserve currency.
The coming global crisis will sink further and further into the abyss until the nations agree to a monetary reset and the only way they will ever agree is if that new monetary reserve unit is not controlled by the USA as it is now.