I've never gotten much flavor contribution from whirlpool hops. Personally, I don't think the aroma from whirlpooled hops is as stable and long lasting as the aroma gained from late boil hopbursting and dry hopping. I've also never experienced any grassy vegetal flavor from dry hopping. I dry hop all my IPAs and typically leave the hops in the keg until it kicks.
If you're dead set against dry hopping it, I'd try something like 1/2 ounce at 10,8,5,2 and flameout. Just MHO. I think you're right though, it's a very mildly aromatic hop so it will take a lot to get big aroma. That's why I'd go the hopburst route.