Using Company-wide JIRA Roadmap Private Teams?

Application Services

I have reviewed using Teams in Advanced Roadmaps, which describes using Private and Shared teams in JIRA Advanced Roadmaps.  Private teams only exist in plans and Shared teams are visible across the organization and can be assigned to work on multiple plans.  The caveat is that once shared teams are created, they can't be reversed, perhaps impacting the JIRA Plan ecosystems.

• Is it less risky and yet still robust to use private teams by adding company-wide Boards (Scrum and Kanban) to a plan source?  I want to emulate the shared team functionality across the company without the risk of breaking things. 
•  We use a higher level custom initiative, "SAFe Epics" above the standard Epics/Features.  Would adding another initiative level allow private teams to be more manageable in Roadmap views?

Application Services

Atlassian support answered my Shared Team concerns via their comment below:

"I believe there may be a misunderstanding of the article. The "irreversible" caveat in the article refers only to converting a private team to a shared team. What this is saying is that once a team becomes Shared, it may be assigned to Projects that are outside the scope of the original Private team, which would make it impossible to convert the team type back to private. The team would have to be recreated as a Private team and reassigned again in order to revert it to Private."

That works for us, since,"... setting a private team to shared team is just an administrative thing.  Just remember that team names must be unique, so you could have "The A Team" that is private and "The A Team plus" that is shared, but you can't have two teams with the name "The A Team."