I don't really care about BC break, I still didn't tag anything. And to be honest, the flexibility it brings outperforms this (I was always tired of writing all those factories to create object repository, plus the performance impact can be pretty high if you had lot of routes).

Actually I think it makes more sense now. The ObjectRepository is always the "starting point" of the traversal. But in the config, it makes more sense to specify an entity type (it's more intuitive), than the repository. Hence my point of renaming "resource" to "resourceType".