@Chr1sG, yes there are existing workarounds.
The case for this is really about reducing complexity, i.e. not having to create additional lookups, and avoiding having to remember that a particular field is actually modified from a related entity (which is not how I like to build things). It’s a maintenance headache.
I have actually found myself forgetting why I created a particular lookup or relation, and deleting it, only to (re)discover later that it was added it to perform some kind of work-around (usually in a script or rule).
If we were able to notate each field and DB, that would also help with this situation.