Scene Camera view mode to show extents as box instead of zooming.

I have a large scene, and I'm putting in a bunch of cut-in scene cameras. I'd like to be able to lock the scene view to the full view, and have the camera, instead of showing what it sees, I'd like to see it as an outline (or just like it shows now, but not automatically having the scene zooming in.

in other words, I'd like to see the camera extents shown as a box, but the view to remain pegged to my zoom level of the artboard, not the current camera.

for example - the attached images is what I want to see - without automatically zooming full-frame to the "camera" view.