Limiting the role to stored procedures sounds like it kinda defeats the purpose of using dreamfactory. The main reason for using it is to get the REST API.
So far I’ve tried to create a table, mapping user.id to SSN, and populating the table on user.register.post.post_process. I managed to write the SSN to the table, but not the user.id.
Another thing that I tried, which would make things a lot simpler if I got it to work, was to create a lookup key for the user on user.register.post.post_process. I tried doing it according to this, but it didn’t work.
Both approaches would work if I could get/set lookup keys for users via scripting, but I still haven’t found a way to do that.