I had previously requested that, when switching between layouts, the zoom was preserved so I was always looking at each layout the same way.
But for now I’ve found a solution that works very well for me! I’ve assigned Alt-Z to “Page Width” (since Z is Zoom In) and Alt-X to “Whole Page” (since X is Zoom Out). It’s a helpful way to compare layouts, especially “Whole Page.” Alt-Z was Custom Zoom (can’t remember whether that was default, or whether I did that), but I prefer just using Z and X anyways.
I’m finding I use this mostly to quickly compare both full-page layouts (a quick check before printing) and page-width zoom to compare the header materials of layouts. Posting this here if it’s helpful to others!