Simple Access
Users want to be able to access configuration in a unified way both in SE and EE. EE may provide additional mechanism, such as injection, but the SE mechanisms should work as well, so any code written in SE is fully portable to EE as well. This can only be achieved by providing a static accessor, e.g.
Configuration config = Configuration.current();
The call above should work exactly the same in EE. To enable this the static call must be delegated in the internals of the singleton, depending on the runtime. In EE the executing component can behave contextually, or even be loaded within the CDI environment (at least for post loading, application runtime aspects, but not earlier).
Additionally in EE it should also be possible to inject Configuration, which gives you the same results as the call above:
@Inject
private Configuration cfg;