I do not think this nozzle is safe at operating and design condition because you already found the hot sustained load have trouble.

First, you check if you took out the lift up rigid support to get more reasonable hot sustained case load on nozzle.
Second, if you have FEA program, you check the nozzle stress with FEA program since the result of WRC107, i think, is generally conservative comparing to FEA. If you can not use FEA, you would be better add a spring support adjacent of nozzle.