Thanks for the replies. For those advocating that it is no big deal to takeoff a little bit overweight....I have done plenty of that in the old days and am well aware that there is likely to be little real world consequence.
But I now work for a company where a minor exceedence a limitation is a huge deal with serious consequences. So, the limits will be respected as things are closely monitored on these advanced aircraft. No need to discuss further.
As for the aircraft, the limit was max structural weight(I'm sure most figured that out as I stated we were at our max taxi weight). But we must have been close to runway limits at no derate or ATM was allowed.
There have been some accidents caused by excessive use of brakes prior to takeoff but those were steel brake. What about carbon brakes which supposedly like some heat.
I am not aware of any maximum brake unit heat prior to takeoff but I was also concerned that peak heat would happen after takeoff and we might end up having to extend the gear if we got a brake temp warning. Are these realistic concerns? 4 hours after takeoff when I returned from my crew rest, there was still some heat indicated on the brakes. That being said, I have noticed in the past that it does take a while for them to get down to zero.