What features would push you towards re-operation for completion staging vs observation for a premenopausal woman with stage II borderline tumor of the ovary with capsule rupture and no other evidence of gross residual disease?

I would only reoperate if there were a survival benefit, symptomatic benefit, or change in treatment regimen. From the description, it doesn't seem like this meets any of those criteria.

Probably none. What's the benefit of upstaging her with another surgery if there's nothing to resect on imaging, and I'm assuming is asymptomatic?