Support for private instance?

Hello, I am considering using Pleroma to replace the now-discontinued Path app for private sharing with family and friends.

A private instance would have:

• no public pages (user profile, public timeline, etc)
• no public APIs
• no federation

But would keep the Mastodon APIs to use with the iOS/Android apps.

This is a different use case than Pleroma/Mastodon/etc, but still a useful one to let people control their data.

Should I consider a fork of Pleroma, or a config setting that switches off public & federation?

Thank you!