I usually cut my blanks 1/8" - 1/4" oversize and use the mill to trim them down. Sanding that much down might be problematic, guess I'd just have to make the blanks closer to actual size.
But your method would solve one problem I've had, I cut some bloodwood blanks at about a 45 degree angle, and 3 out of 4 times, the mill broke a large corner off, ruining the whole blank. Thought I used too much pressure, so I tried going gently, but same thing. Probably needs to be sharpened again (what a pain), but sanding would solve that.