Support simple user macros in Confluence OnDemand

The Confluence OnDemand environment does not currently support user macros, although templates are supported.

User macros provide a way for the customer to insert custom HTML and JavaScript, which due to the security model of OnDemand (where Atlassian uses the same web interface for system administration), is actually a security vulnerability due to the possibility of cross-site attacks by malicious customers against our administrative accounts.

Would it be possible to support simple user macros in OnDemand, that operate like a template (i.e. layout, content, supported macros) but are called by a user defined macro instead?