I wouldn't put a sand sifter of any in your refugium especially with a DSB. It kind of makes it all a moot point when the sand sifter will decimate the populations you are trying to achieve by making a refugium with a DSB.
The starfish will basically eat "everything" in the sandbed (they are big eaters, I've known many to starve in 100+ gallon tanks), and most sifting fish will eat all the pods too.