If I remember correctly, I believe the smaller Honda cargo rack also had a 6 lb rating. I have loaded my MP3 with a loaded tour pack and duffle strapped to the top of that. That weight was tight against the back of the passenger backrest and directly above the cargo rack mounting bolts.

I don't hang additional luggage on the back of the tour pack which would put more weight further back from the mounting bolts, to the rear most edge of the rack. No issues to date.