Designate uses a concept of "sub-teams" to help distribute the work of design reviews, bug triage, code reviews, progress updates, etc for large changes to the Designate Code Base
Each SubTeam has a SubTeam Lead, who is responsible for driving the direction of the work, coordinating developers, and reporting progress to the PTL.
The SubTeam Lead will have the overall architectural vision for the feature being developed
Each SubTeam will have an overall spec in the designate-specs repo  in the sub teams folder.
This will be updated to include links to sub specs, and show the current assignees of work items
Each SubTeam will then add specs in the sub team folder created when the main review was created.
Once a member of the team gets a work item in the sub team, they will write a new spec, and it will be reviewed as normal. However, the only people who will approve the sub team specs should be the Designate PTL or the SubTeam Lead.