LwDITA DTD/feature questions

Colleagues,

    

    A few questions about the Lightweight DITA DTDs and LwDITA features
    --

    

    - The content model and attribute set for <data> is different
    in maps and topics (content model: <data> in <topic>
    allows #PCDATA; <data> in <map> does not. And the
    attributes are different). Is that intentional?

    

    - LwDITA does not provide the DITA filtering attributes? (O.K. with
    me; just confirming).

    

    - LwDITA does not provide a generic metadata container attribute
    (e.g., @outputclass)?

    

    - Should we provide @processing-role on <topicref>? I'm
    thinking of the use case of referencing a "keydef-only" ditamap
    (@processing-role = "resource-only").

    

    -Alan