It makes one wonder if all the minute tinkering with RTOW tables, and the now infamous I-Pad takeoff calculations, to the nth degree, will in fact give you all the umph you'll need when you need it. The ground school instructors and OPC SFI's would red ink you for missing a couple of 100kgs here or there, and given the payload was probably at least a 1000kgs light anyway.......
It's interesting, as I'd not heard of this effect before, nor had cause to think about it. Crunch the numbers and check the settings as the engine spool up. If the engineers have compensated for this effect in their RTOW tables they seem mighty clever. It brings the whole concept of 'ball park figure' into a new light.