Owwww... I must say I also thought this could be a great feature but it's not what I thought.
When I dynamically add a "HUD" layer to a layout, which is a global layer I created and designed in another layout, I was honestly expecting it would create the global layer with everything I designed.
I thought this was meant to be a solution to avoid many unnecessary layers through out every layout on the project.
Is this something we can expect in future updates?
I was the one suggesting this idea in the ideas platform and it was "closed" and I can't see it anymore, but, sorry to say, it's not what we find useful.
I can give many examples but please let me know if it's something doable.
Thanks!