I have a doubt about this configuration. The SG uses the MED attribute to BB1/BB3. As others have discussed, it is possible to use other attributes (i.e. local-pref), but let's go with the SG solution. We will use the MED attribute.
My understanding is that MED is a Non-Transitive attribute. So, like local-preference, it should not go beyond the next AS.
However, the SG is also using no-export to keep it from passing to other AS's. Isn't this a redundant command? Is there a need for no-export?