Attaching rack to seatpost QR

I'm attaching a pretty standard cargo rack (Bontrager Back Rack 2) to a hybrid bike that has a compact frame - one where the bike frame itself is pretty darn low in the back and there's plenty o' seatpost. I've got eyelets down by the rear axle, so that's good. But I'm thinking I need to attach those silver arm thingies (the metal strips that have one 90 deg twist to meet the frame) to my seatpost's quick release skewer. Anyone know if this is bad idea? It seem an ideal place to mount to and it wouldn't be carrying any weight. The actual weight of my cargo would be sitting on the rear triangle at those eyelets.

I have often attached the top of the rack to the seatpost quick release. As you say there is little load in this area.
I have used these bikes for offroad touring and have full confidence in this mount, which can't be said for the load bearing eyelets that sometimes seem to be an afterthought on the dropouts.