This could maybe be overridable through defining a custom extension point
"patientHeader.editPatientDemographics", see here.
This is the place where this extension point is defined in the Registration App module:
You may try to define an alternate one in your custom module and validate that it is picked up (or not) and hence that it indeed overrides the current setting (or not). I suspect that it may work, but would then be unpredictable. I guess some order should exist for the extension to be preferred based on its order.
@darius @mogoodrich, thoughts?