David Crossley wrote:
Also Cocoon will cache the results of each pipeline, so if
the xincluded file changes, then the changes will have
no effect.

The XInclude transformer is not cacheable. This is good with respect to the problem you identify, but bad with respect to performance issues, since the include is processed regardless of whether the included document is changed, thus the generated document can never be cached.

For simple includes we should use CInclude instead, this is cacheable, however, CInclude does not allow the use of XPath so does not fit this use case.

Ross