Ocean Wun Zero - very good point. The amount of CAS that DSA have is ridiculous bearing in mind the activity there. Every time I fly over it there isn't a single airliner on the ground!
I think you can write to the CAA-DAP at Kingsway, and suggest to them that the CAS is unnecessary, and they will take this comment into account when they review the airspace, which I think they do one year after inception.
They seem to be very open to people's view, so please write if you feel strongly about it. I'll do the same, because the amount of CAS that has appeared around every regional airport within the last 3 or 4 years doesn't seem to be sensible, and DSA's is just an abuse. A Transponder Zone would be far more appropriate in this case, or maybe nothing at all.