Earlier quoted context omitted.
You want more than a boolean flag. You want to be able to enable features for certain customers. For example, you might want to roll out a feature to only the US or only English speaking users because you haven't internationalized it yet. Or you might want to enable it for select customers. Or all sorts of other examples. You may also want the ability to gradually roll out a new feature over time. This lets you test…
Possible to have a feature requiring a dependency update that may be mutually exclusive with the previous dependency graph of the former feature set?
That's not really the domain of feature flags in their typical use case. That sounds like you would need to deploy multiple versions of the app and switch between them at the load balancer level or something like that.