The largest black burl spot's white splotch on the lower barrel, it probably had a bit of a crater. When you hit it with CA, the crater is still there. Then, you sand the CA and it collects in the crater. Next, you slather on another layer of CA, but it seals the white dust from the sanding into the crater. So, the white dust gets entombed into the crater. If you feel a indentation in the wood from some spalting or a heavy burl splits the wood, mix in some fine wood powder from when you turned the blank with some CA to fill the spot, similar to a powdered inlay. Then sand it even with the rest of the surface.