Request from wsit forum:

I just installed on another machine, and I guess the wsit plugin has
been updated such that now in the 'Edit Web Services Attributes' dialog
it does not present options on the client that were not expressed in the
server WSDL. However, what do you do for example when you want to sign a
web service even though there was no explicit policy in the wsdl? 

Perhaps some sort of option on the dialog to display all options even if the
service doesn't ask for them might be an alternative.