Ok I re-worked this.
I'm not adding branches I don't want anymore.
But I still need to access:
$(ulc(aor=>user_agent)[INDEX]) from within the branch route to tweak some headers for specific user agents.
The ulc INDEX does not match the Branch INDEX.
How can I pass an information into a branch route which is specific to a branch route like the user_agent associated with the registration to which the call is sent?