I am strictly refering to the use of “show/hide in detail”
Layers are no concern.
eg. You have a ready layout, containing 5 detail views. You make a copy to use it for another detail of the same scene (the geomety for that new detail is currently hiddenInDetail) Then after duplicating the layout, one has to go in all the detail views one by one and repeat the task of hiding and showing the identical geometry to get what is needed.
so I would suggest a command that picks up the shown geometry from one detail view (select detail view in layout) and transfers it to another (again pick detail view in layout)
not quite sure what you are referring to here; Until now from my observation, copying a detail view always appeared to keep the same geometry hidden as the original.