When there's a whole list of backordered parts, you can ask Vans to ship what they have.
I came up to the stage of the build where I needed two of the back ordered items and they happened to be available. Yes they want to wait until everything is in stock however, the parts don't do me much good sitting on the shelf at the factory. I asked for them to be sent my way. Granted I had to pay for shipping, but the parts are no longer holding up the build.
My RV8 fuselage kit was shipped in October, and I'm still waiting for a couple things. Most got shipped when I needed 2x F-804G a month ago.