So, it looks that all security practices will be incorporated when this
nosamplecontent run mode is used. But you can enable CRX-DE by
following:
https://docs.adobe.com/docs/en/aem/6-1/administer/security/security-checklist/enabling-crxde-lite.html.
In case, you need to only remove geometrixx content, I do not see an
option by run mode. I will verify internally and let you know.