This turned out to be a much bigger ticket than anticipated.
The goals/use-cases described in the JIRA ticket are quite simple and are tested for correct behaviour in t_scheduling_units.py SchedulingUnitBlueprintIndirectModificationsTestCase.
The biggest changes happen "under the hood" and should have hardly any effect on the API or outside world. Bottom line of the big changes: We have no more duplicate storage of the specifications_doc, but a specifications_doc can be imported and exported. The information is encoded in the Task graph itself.
I added little datamodel ticket TMSS-1044 to this merge request.
Edited by Jorrit Schaap