Could you explain your workflow using BRDF, and what application you're using? I just want to know the real world use case for this kind of data.
I'm open to expanding the database to include BRDF data as well.
I contributed a tiny bit to pbrt[1], and one of the things I loved was that if you just plugged in physical values you almost always got great results with minimal tweaking.
The Octane data seems most complete at first glance (with complex IOR etc), but for things like milk and blood I expected at the very least some absorption coefficient for the translucency or similar.
