No runway analysis no reduced Takeoff N1.
There is no legal safety net if you end up in the fields.
Your manuals will cover you for the ZFW and the TOGW you decided-accepted, but if you end up with an overrun after a RTO using less than full N1, they will ask you how you ensured the balance field requirements. I do not think there is a manufacturer's page anywhere that will save your neck.
