While I agree that this should be the best practice, there is a big difference in the framework between what we "allow" and what we "recommend".
There is lots of stuff you can do with the framework that is really not a good idea, thought some might disagree. Things that we recommend should be documented in the Best Practices Guide. Other things we don't want to make more difficult, IMO, that this is important because of the comment about disagreement above. There are pretty much always good reasons why we do things the way we recommend in the framework, but those recommendations have evolved over time and will continue to evolve as well, and not allowing things we don't recommend stifles this and limits opportunity to progress and improve.
That is of course a generality, and there is a clear best practice here that should be documented and it probably won't ever change, but I'm still against forcing on a matter of principle.