Currently the only way to do that is to use the "default" profile (http://localhost:8080/designer/editor/?profile=default&uuid=xyz)
and provide the uuid yourself, but again as previously mentioned the "default" profile only saves the process json onto the file system (when you press the save button in the designer toolbar).
Note that "7ef4023f-2f14-4c17-a999-78c992b29ffa" is only really usable for Guvnor, as it is an unique id of the rule asset it created for you and stored in it's JCR repository.
If there is push to create a standalone profile which can interact with Guvnor, then we could add that in but it would not be high on our todo's right now.