Bolty,
Um, we ARE talking about INDICATED temps, right?
Bus brakes REGULARLY exceed 300 C with no problems.
600 C is met as well with no sweat. That's indicated from the core of the brake and is our prime (actually only) indicator (aside from flames or deflated tires).
800 C is the AMM special inspection limit if you haven't melted a fuse plug. That leads me to believe that exceeding 700 but not 800 would be OK for flight provided the fuse plug hasn't melted.
This ain't from someone I know, it's in the book.
PB