I recall questioning your quotation several years ago. It looks like a sentence is missing. What does "resolved at the centerlines" mean? What's that "s" doing there at the end of centerline? I think the "resolution point" is the intersection of shaft and exhaust centerline. But what if these two lines do not intersect? We asked for an interpretation from the NEMA people. The issue was never "resolved" (ha).
Not only is the resolution point not settled but even the term "resolution". When I think of resolution I think of tranposing forces and moments to a new point where forces create moments. If you look at the example, that is not the case. But when you think of it, it's all artificial anyway. There is no load path to this arbitrary point inside the turbine. It's all math and rules. Just follow the rules and no one will (should?) get hurt.