Across the board would probably be the most correct approach, easiest would be in the bittering addition. However, iirc as david_42 has mentioned in the past, it is very difficult for most people to distinguish between 30 and 40 IBU (I think it was a 10 IBU difference, david correct me if I am remembering it wrong), let alone 30 and 32 or 33. If the AAU value is low just add a few grams more in the bittering addition.
Event Horizon ~ A tribute to the miracle of fermentation.
Brew what you like. Do this, and you will find your inner brewer.