How to customise the Patient Registration page?

For now I have this:

"legend": "Person.address",
"fields": [
    {
        "type": "personAddress",
        "label": "registrationapp.patient.address.question",
        "widget": {
            "providerName": "registrationapp",
            "fragmentId": "field/personAddressWithHierarchy"
        }
    }
]

Should it become that?

"legend": "Person.address",
"fields": [
    {
        "type": "personAddress",
        "label": "registrationapp.patient.address.question",
        "widget": {
            "providerName": "registrationapp",
            "fragmentId": "field/personAddressWithHierarchy",
            "config": {
              "manualFields": [
                "Foobar"
              ]
            }
        }
    }
]

This doesn’t produce any result. I am sorry if this is obvious, I’m just really unsure about this config logic in the widget. But from the widget class that you pointed out above in the thread, it seems that it should be at the same level as fragmentId or providerName, which is why I put it there. I’m not sure if you really meant uicommons in your snippet, in which case I may need more info here I’m afraid.

Another issue is that the address template in Admin > Manage Address Template is reset to the default one each time I restart Jetty. Have you ever noticed anything like that?

Thanks for your responsivness.

EDIT Being a bit stuck, I tried to debug PersonAddressWithHierarchyWidget.java but this was never reached. When exactly is this Config object instanciated/read?