For those interested in the answer. The issue is that the input to the "Create Edge" workflow is in Array of "Properties" format vs an Array. I modified the input to the workflow to be something more like:
tempProp = new Properties();
tempProp.put("index", 0);
tempProp.put("name", exerciseIdentifier);
tempProp.put("portgroupId", instancePortGroup.id);
tempProp.put("type", "uplink");
tempProp.put("primaryAddress", "192.168.1.44");
tempProp.put("subnetMask", "255.255.255.0");
propsArray.push(tempProp);
Than passed the propsArray into the workflow. That did it. New ESG created in NSX.
Good luck all.