Greetings
The Airport Authority, can give a dispensation, for few landings above the PCN, it is common practice.
Yes it does shorten the runway life, but the time scale is more a matter of years than months.
Now if you do the computation you will see that the total weight is on the main wheel, and if you look at the table you will see that the nose wheel is taking around 7% of that total weight, so you have margin equal to what ever the nose wheel takes.
