The EditCustomReportColumnAction class is a copy of EditElementInCollectionAction: Try to do this class generic enough in order to be used in for any transient class, or at least remove the repeated code.
SaveCustomReportColumnAction and RemoveCustomReportColumnAction: Make them generic for any transient model
Moving data from UI to model object? In that case code like this in GenerateCustomReportAction will not be needed:
Develop must have the option of put their transient class in any package (not just model or entities packages). We have to improve the method AnnotatedClassParser.getClassNameFor(). Maybe using a propetie in xava.propertie or using the Package JDK class are good options.
We have to document the new possibilities of transient objects in the wiki.