I totally agree. I look for this improvement once in a while, when I do changes and improvements in my code. I hoped I just hadn't noticed some other way to do it "in memory". It seems very unnecessary with this disk access.
I filed a feature request at https://www.adobe.com/cfusion/mmform/index.cfm?name=wishform.
Perhaps more people wish for the same... and evntually the XML import functions will be able to handle an XML datatype object as argument.