Hi Marco...
Just as you stated above, the best way to pass data along in the workflow is with Relevant Data (OR Input Parameter data, if exists). As for the data used in modifyPerson and enforcePolicyForPerson (e.g. "Entity"), this should be handled for you...but if you wanted to modify that object/data before/between/after those Extensions, you could do that in a Script node. You'd just need to call .get() to get the object...then manipulate as needed (e.g. .setProperty("foo","bar");), then call .set() to pass the modified object back to the workflow.
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Grey Thrasher
IBM
Costa Mesa CA
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