How do I open the DTL Editor in a browser without the banner (e.g. in Studio Mode)

I want to embed the DTL editor in a third party web application.

If I open up the DTL editor then the full management portal banner is displayed.

http://localhost:52773/csp/healthshare/user/EnsPortal.DTLEditor.zen?DT=Foo.NewDTL1.dtl

If I open the same DTL in studio then I get just the editor, the banner is not displayed.

The DTLEditor page has the property studioMode that controls the banner display, but its not obvious how this is set.

Q. Is there a way to control that property without extending and shimming the page?

Q. Could there be a URL parameter or header that controls that value?

Q. If I have to shim the page then any suggestions on the least fragile option?