Simple Team Process : Is it possible to change the Related Artifacts > associate Workitem work item creation dialog ?

I customized the SImple Team Process by adding new WI types.
But, surprisingly, when, in the Pending Changes view, I use the context menu Related Artifacts > Associate WorkItem > Create WorkItem, the dialog box does not propose the choice for the work item type.
What I would like to do is to use the dialog box used in Scrum Process or Formal Management Process (which proposes to choose the WI type)
How can this be done ?
Thanks a lot !