One thing to keep in mind with Ford's compromise is that since this is meant to be a street car, turbo lag is undesirable, and the larger the tubing and intercooler area is, the more cubic area there is to fill, resulting in more turbo lag..
Fiesta St2014
Those runs were with 230 WHP (stock is 175 WHP) on a basic tune still with the stock exhaust system. More supporting mods coming to make it over 250 WHP to see if it will run 12's!