KERML — Composite feature values can have more than one owner

7.3.4.1 (Features Overview) says

Values of a composite feature, on each instance of the feature's domain, cannot exist after the featuring instance ceases to exist.

and 8.3.3.3.3 (Feature) says

isComposite : Boolean
Whether the Feature is a composite feature of its featuringType. If so, the values of the Feature cannot exist after its featuring instance no longer does.

but the spec doesn't seem to say anywhere that the values cannot be values of any composite features on any other instance of the feature's domain ("single owner", "tree" property of composition), as typically expected.