## Summary  This is the other approach for unifying default and sync lane #25524. The approach in that PR is to merge default and continuous lane into the sync lane, and use a new field to track the priority. But there are a couple places that field will be needed, and it is difficult to correctly reset the field when there is no sync lane. In this PR we take the other approach that doesn't remove any lane, but batch them to get the behavior we want. ## How did you test this change?  yarn test Co-authored-by: Andrew Clark <hi@andrewclark.io>