Is it possible to edit multiple ACM fragments as XML?

I have opened a document from ACM that includes several bursted objects or fragments. Selecting Edit > Edit Selection as XML Source results in:

<cards>

<xi:include href="x-wc://file=0000119577.xml" xmlns:xi="http://www.w3.org/2001/XInclude"><xi:fallback><!--Fallback markup for "x-wc://file=0000119577.xml"--></xi:fallback></xi:include>

<xi:include href="x-wc://file=0000119576.xml" xmlns:xi="http://www.w3.org/2001/XInclude"><xi:fallback><!--Fallback markup for "x-wc://file=0000119576.xml"--></xi:fallback></xi:include>

<xi:include href="x-wc://file=0000119575.xml" xmlns:xi="http://www.w3.org/2001/XInclude"><xi:fallback><!--Fallback markup for "x-wc://file=0000119575.xml"--></xi:fallback></xi:include>

</cards>

Typing "edit -current -untagged" in the Command line presents similar results. Is there a way to edit those fragments as XML?

Thank you,

Lisa