I just picked up a 50lb bag of commercial quail feed from a local shop. It's from Tucker Mills, but the protein content is only 20%. They didn't have any better options that were unmedicated. I've got some newly hatched chicks so I figure I need to up the protein.
I've seen mention of supplementing with soy, greens and other things. The feed store did carry 50lb bags of soy meal but I don't need that much. Ultimately I think something that I can consistently mix into a large-ish quantity of the layer feed would be preferable. I have pure, unflavored whey protein, but the lactose content may be problematic.
Perhaps soy is the best bet? Is there an ingredient that's cheap and readily available at grocers or on Amazon?