Aha, yes with partially-overlapping streams it makes more sense.
Then again, the next thought is that the selection always lists the versions, but there is no direct connection between the version URL and the concept (i.e. purely based on the global configuration and selections I can’t fully know which concepts are versioned), which means “resolving” the version selections to a concept either needs à priori knowledge about (all the) possible versions (yes, this should already be “available” in the local configuration) or worst case needs to resolve the version selections to see which concepts they actually refer to.
Edit: changed “non-overlapping” to “partially overlapping”