Setting sag on a F32 150 Talas RLC

So for the first time in my life I have actually read the instruction manual for my new fork. It is a 150 talas. I set the sag in the lowest travel setting but since I will be riding it in the 150 setting for all downhills shouldn't I adjust the sag in that setting? But if I do this it is way off from what the air pressure recommendations are. Can anyone shed some light on the proper technique?