Hey there Bolty,
Stop scaring the you know what out of everyone!
The fuse plugs should not melt earlier than 800 degrees C (1472 degrees F). That being the limit in the maintenance manual.
They MAY melt earlier, but hey, some times you catch a break.
As to use of auto brake MAX, there is no reason to say that setting will cause an overheat if you are heavy. I've never seen an overheat when auto was used, but I have seen a few when a pilot stomped the pedals.
In any event, the Airbus brakes have always stunk and they do funny things if you just look at them the wrong way, so what does it matter?
PB