$metadata document and RDE devices

Hi everyone,

The Redfish specification requires a Redfish implementation to expose its metadata document.

But together with RDE devices the final set of schemas may become varying (for example if
a system implements pluggable add-ins with non-dmtf-defined schemas).

Moreover, an RDE device provides schema binary dictionaries instead of XML,
so it may be not possible at all to update the metadata document in this case.

In order to comply with another Redfish requirement the RDE specification provides mechanism of getting
formal metadata URI for the data in response (via Link / described by header).

So, in the end a redfish client is capable of getting schema for the requested data. But not a generic odata
client which searches for schema in the $metadata document.

Should Redfish implementations for such cases somehow tell clients that the metadata document
may be incomplete? Or even more, Redfish implementation should gather RDE device schema URIs
in a special collection where clients know they should be?
However, I guess for generic odata clients this may be not helpful either.

Thanks.
Dmitry