I don't think it's worth it.

There are interface docs and tests that describe how the implementation should behave, these comments are just to help readers understand how this particular implementation achieves that behavior: I don't want to add details on the reasoning behind the design that could impose limits. Who knows, maybe it'll turn out using `NSKeyValueObservingOptionInitial` is the best way to do it after all, but if I add a note saying "we can't use `NSKeyValueObservingOptionInitial` here because this and that" others might not take the possibility in consideration.

It's a bit of a silly reason though, so I'll add a note after all if you think the comment is really confusing.