EWM Plan: Different behavior using Parent->Child relation, compare to Tracks->Contributes relation

We automatically create a Tracks->Contributes link parallel to a Parent-Child link. Reason is, to allow an owner of a work item to see "multiple" parents (contributes) tracking the owners work item. With the introduction of this new functionality we plan to change the Tree of any plan from Parent->Child to Tracks->Contributes. The result of the plan should be the same as before, but with multiple contributors visible.

When performing tests with plans we figured out, that following problems occur:
It is not possible to see the full tree of work items with Tracks> Contributes or Contributes->Tracks as it is displayed with Parent->Child. If the plan related item is in the middle of the work-item-tree, either the lower or upper part of the work-item-tree is missing.
In case of the relation ship Tracks>Contributes, the work-item-tree is build up in the wrong direction.
The direction of the link Tracks --> Contributes is the opposite compared to Parent>Child (assumption: a Parent is Tracking the Child / A Children is Contributing to the Parent)

For detailed explanation see the attached presentation.
Page 1 shows the work-item-tree which was used for testing, with the plan result when using the Parent>Child tree.
Page 2 shows the plan based on the Parent>Child tree in relation to the Tracks-Contributes tree and in relation to the Contributes->Tracks tree and describes the problems in the used example.

Case TS005734003 is closed with the conclusion that an enhancement is needed.
Result from the Case:
Parent -> Child tree should be kept in the plan as it is today and further relationship (slave relationship) (Contributes -> Tracks) should be added as an relationship option in the plan. With adding further relationships, the Parent -> Child tree should only be extended downwards but never upwards. This would ensure that the displayed content will stay as a tree and not become a graph, but will include further items and more detailed information, therefore.

Benefits:
-Main benefit is, that additional items which contributes to the item of the plan can be displayed, to consider them in the planning phase. (e.g. Items which are tracking my item, because they want to participate on my activity)
-2nd benefit is, that the popup menu "Create Child Work Item" (on the left side, beside each item in a plan) still creates child items with Parent-Child relation ship and not items with the relationship which is chosen for the plan view. Reason: In the planning phase, child items will be created to address additional needs to other parties.
-3rd benefit is, that the icon "Create Child Work Item" (on the left side, beside menu icon, beside each item in a plan) creates a child which is visible in the plan.