TEX11 — Aggregate Entity shouldn't compose Entity Payloads

In the v1.0 spec AggregateEntity composes EntityPayload and ComposeEntityComposes ShapedEntity.
AggregateEntity has documentation "content grouping" which suggests that a looser, by reference relationship would be appropriate.
The strong, by-value relationship that it has, enables recursion. This is probably wrong and certainly leads to PSM implementation issues.

AggregateEntity to group entities by reference

As the CompositeEntity class is described as being non-recursive, AggregateEntity is clearly intended to model recursive cases as well as modelling loose groupings in general.
There should not be anything to preclude an EntityPayload belonging to more than one AggregateEntity.
EntityPayload instances should exist in their own right and be referenced by AggregateEntities (directed association, zero-to-may at both ends)..