BBO: Design doc follow-ups

Certain non-blocking items were pulled out of the initial MR to handle here.

Deliverables

• gitlab-com/content-sites/handbook!14815 (comment 2696767786)
• gitlab-com/content-sites/handbook!14815 (comment 2696767787)
• gitlab-com/content-sites/handbook!14815 (comment 2699405671)
• gitlab-com/content-sites/handbook!14815 (comment 2699419667)
• gitlab-com/content-sites/handbook!14815 (comment 2692130197)