what I think we are most likely to see is a split in the exchange rate like Venezuela uses. One lower one around the current official rate for necessities, food, and exports, and another one closer to the current Blue rate for non essential imports, and travel and tourism abroad. If this is implemented I would expect it to cause the current Blue rate to move to a similar percentage above the higher official rate that it now holds against the single official rate(60%), so if the second rate is set at say 7.5, and the Blue moves to 60% above that you have your rate of 12 exactly.