Reuse and extend MDG SysML (e.g. block definition diagram)

[Pegasus]

I do have created my own MDG based on SysML. Unfortunatly it seems not be possible to say something like use MDG SysML and extend it. No metaclass have to be an UML Type and use SysML by Generalisation like described in Help(Extension ...). But on my own defined Diagramm ( metaclass Diagram_Logical)  i do have the effect that the Arrow(deals with FlowProperty in SysML) on the Port-Element is not shown. The link of the same Element in a SysML BDD shows them. I believe that there is a dependency to a Shape-Script in relation to the diagramtype. But i do not know where and i don't want to reimplement SysML-BDD appearance. How can I reuse direct the MDG SysML diagramtypes in my own MDG with a different name to connect it with my own toolboxes and to be select by e.g. the New diagramm Dialog (Select from <myMDG>)

Thanks 
Pegasus

[KP]

How can I reuse direct the MDG SysML diagramtypes in my own MDG with a different name to connect it with my own toolboxes and to be select by e.g. the New diagramm Dialog (Select from <myMDG>)

Thanks 
Pegasus

Unfortunately, it is only possible to extend EA's basic built-in diagram types (as listed link:here), not extended custom diagram types.