"should we expect the embedded..." <- Well, the goal is to never have a 2.0 (or at least not for a time much longer than a year or two), so this is unlikely to happen. Also, while the trait itself doesn't enforce it, the implementors can still implement it and the users can still require it. So the gain is very likely not worth it. I'd say that doing it now would be less pain than in 2 years haha