>  If I am mistaken and this information is available then the same approach can be taken as during deployment by 
> iterating over the files and removing only those that match.

You should be able to set the [`destroyOptions`](http://docs.xebialabs.com/releases/3.9/deployit/genericPluginManual.html#generic.AbstractDeployedArtifact) for your deployable type to "uploadArtifactData". That should allow you to access the reports that were deployed (using `$[deployed.file}` as usual) to determine what to remove.