I think it could be useful to be able to delete (or outcomment) stuff from container configuration using Cargo.
Background and use-case:
I want to disable the AJP connector in Tomcat, and the only way to do this in Tomcat (that I am aware of) is to delete (or outcomment) the AJC connector element from Tomcat server.xml. This is currently not possible to do with Cargo without replacing the whole file (server.xml).
See Cargo mailing list for additional details.
I am not sure how this should be implemented i Cargo, but I consider this improvement to be an extension/variant of XML replacements in Cargo