By default new Classloaders for transformations (Reformat, Joiners, ...) are created for each graph executions, even each component has own ClassLoader to load transformation class. This behaviour can be inconvenient for example if you want to share POJO between components. For example, a Reformat component creates an object (from a jar file on runtime classpath) and stores it into dictionary. Another Reformat component get the object from the dictionary and tries to cast to expected class. ClassCastException is thrown due different classloaders used in the Reformat components.
New execution flag should allow to share classloaders between components (Reformats and others) even between different graphs.