after looking up XML-RPC#Data_types on wikipedia I encountered the following "workaround" to represent associative arrays in XML:

<struct>
  <member>
    <name>foo</name>
    <value><i4>1</i4></value>
  </member>
  <member>
    <name>bar</name>
    <value><i4>2</i4></value>
  </member>
</struct>
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Is this part of the scheme your problem?

In my eyes it's XML which is pathological here, and CPAN modules just try to reflect the structure to avoid ugly bugs caused by information loss when cross transforming data...

For instance:

• Can you guaranty that no implementation XML-RPC-parser will ever try to pull information out of the order of the "members"?

• Do they handle repeated keys alike?

And if you think it's so well defined, so why don't you just hack your own map_to_pathological(%hash) routine which simplifies your task?

CPAN authors might show interest in your patch, or you publish your own add-on module.