Extending SRCreationPG OA Framework Page

I am looking at applying some OA Framework extensions to the SRCreationPG within the service responsibility. Specifically I would like to put in some default values within the extensible attributes based on the customer for whom the service request has been raised.

Reviewing the structure of the page I am assuming that the entity object that I need to apply the extentions to is oracle.apps.cs.csz.extfwk.user.server.SrExtAttrsEO.

Because extensible attibutes are not rendered until after the user has chosen a specific service request type I have been trying to follow the code logic. Correct me if I am wrong but it looks as though the controller which renders the extensible attibutes is oracle.apps.cs.csz.extfwk.user.webui.SrExtFwkSrTypeCO.