Design of piping systems is separated into two distinct categories - the structural response of the system (in terms of restraint loads and pipe displacement) and the strength of the pipe measured as stress. Most any mechanical engineer will be familiar with the former but the parochial rules of the latter are unique.

That's why you (usually) don't look at stress in the operating case and you don't review restraint loads in the expansion stress range case. I would also question any use of the restraint report from the sus+occ case. But I'm glad you are asking questions about the reports. Keep in mind that you can probably develop your own answer by simply running a small job that tests your question. Varying one piece of data (such as summation technique) will show what happens.