At this point, my team and I have read through multiple trailheads, docs and posts on the following. We have a lot of good ideas, but still a key issue remains.
First, please verify this is the best practices org setup for ISV partners: - 1 packaging org (PDO) that will connect to AppExchange - 5 other PDOs where individual coders can do their development - 1 Staging PDO where all Devs can move their code - We'll use Github Repo as our 'source of truth' --- This means Dev, Staging and Packaging Orgs all get the latest from the Repo.
Second, how do we handle namespace with this model? As we see only Scratch orgs can be made to mirror the Packaging Org. Can we do the same with our Dev and Staging Orgs? If not, there are major conflicts in Github as we move code via Github to/from Packaging Org. We have had this already, and it's quite painful.