The other idea is not a paper-cut but because it’s related I’d like to post it here.
I hope it still lands in the right person’s brain. 
Again it’s a PS paradigm that every panel is movable and dockable anywhere. AND I JUST LOVE THAT.
And it’s super-complementary to Blender’s ideology with one key difference:
Blender treats the different panel structures as islands. Bars, panels and editors are not interchangeable.
Forget bars, that’s limited in PS too, but would solutions like this be from the devil?
They could be dragged and duplicated to the N panel freely.
(I used the scene icon for the View tab and dragged in the Shader options as an example.)
Also they could be removed from where we feel they are duplicate and wouldn’t be used.
Now this is what I’d call customizability!