My suggestion would be some kind of a generic data container, whose scope can be parameterized. There could be some annotation, let's say
that can be applied to fields, or setter methods.
A typical use-case would be, when I want to store some data in a bean of scope singleton, but I need the data List<String> to be session scoped. I could then write a code:
A work around for this feature is creating a generic bean for every scope and using proxy to inject, but I think we could all at some point make use of some feature like this.