@Ed.Kaminski Thanks for the Detailed overview, but i am good. But I have to admit that Delegates can get a little confusing. I will add some thoughts of mine how to approach this, and post the solution as soon as i have time to implement it.
To answer your question about the Multicast:
TMulticastDelegate_OneParam< void , UObject * > FOnSelectionChanged
So Binding of the Delegate has to be done at editor time, my best guess would be:
[AActor::PostRegisterAllComponents](https://docs.unrealengine.com/en-US/API/Runtime/Engine/GameFramework/AActor/PostRegisterAllComponents/index.html)
And only when in editor. And of course also unbind it at some point.
Best
Dominic