It will self learn for idle etc.. under I think it's 40% TPS from memory... but yeah at more then that to WOT it will revert back to the open fuel map.. and no doubt will be too rich... An easy fix would be a SAFC... though not the best approach...
There is no need for larger injectors with the stock turbo's anyways... They will support around 250kw atw's... about where everything stock runs out.. fuel pump, injectors etc...