How to tie an activity hierarchy to actions under a parent activity.

[Pupnsuds]

I want to create an activity block definition diagram, using the composite relationship to denote parent and child activities as such.

(Source: https://www.sciencedirect.com/topics/computer-science/activity-hierarchy)

or as such
(Source: https://sparxsystems.com/enterprise_architect_user_guide/15.2/guidebooks/creating_activity_hierarchies.html)

When I use the composite relationship, EA will automatically create a part property as part of the parent activity. 

Shouldn't it automatically create an Invocation (Action) if the composite relationship is of a child activity to parent activity. Then I can make an activity diagram with the actions from the tree.

Currently the only way I can work through this is to do the following.
1. Create Activity hierarchy, delete part properties.
2. Create invocation/actions within activity diagram.

This is double the work. And in addition, clicking "sychronize structured elements" will repopulate the part properties. There is also no link between the composite relationship and the action created.

Is there a way to either have the activity tree composition relationships to be autocreated when actions (call behavior) for other activites are invoked inside the parent activity diagram?

Or vice versa, create actions in a parent activity be using the composition relationship?