Unity3d - Loading dynamic content

I am trying to understand my options for delivering "dynamic" content on a Quest. The most straight forward option is to have one app that includes all scenes for each environment that might be required. This would allow you to jump from scene to scene as required.

Ideally though, I would prefer to have one main app/scene that is always included but then be able to transition to other custom scenes some of which might be customized based on install (or even scenes added at a later date). It would be nice to be able to add something like a package at runtime.

Any options would be appreciated.