At the risk of being told I know nothing I remember reading the following somewhere
When the 290 was released - 'SEAT are keen for it to be known that the power increase is engineering/ mechanical changes rather than software' this was written when talking about the different exhaust system on the 290 compared to the 280.
This obviously can't be the case with the 300 due to the different torque outputs of the 300 compared with the 280/290. 300 has slightly higher mid range boost whilst maximum boost remains the same which goes someway to explaining why a car with supposedly 20more bhp still has the same 0-62 time.
I thought the 0-60/62 came down another tenth on the 300 compared to the 290.