Well the problem you have there, is finding an ECU that would allow you to lower the boost over time spent at full throttle.

Its not really something you can map around when you are right on the limit of flow for the injectors.

Only ways to make it safe are:
dont hold it flat out
change the injectors and remap
lower the boost at the top end


Harvey has set it how he thinks it will suit YOU, if it was someone who he thought would ignore him and sit flat out, he would have tailed the boost off and lost that person power in the interests of reliability probably.