Are you suggesting a checkbox in the admin-level DNS? On a per-domain level? I'm not sure where you'd put that; the DNS administration screen simply administers zone file lines. Where would you do the checkbox? It really has nothing to do with DNS; it's a per-domain setting. Other per-domain settings are done on the user level. Does this one have to be different?
I suppose if I'd like to see anything else at all, it would be to have MX Records available from the user level even if other DNS settings aren't.
Jeff