Change the layout for multiple pages or the entire project in a single action

What's the hassle?
I've just upgraded a project to Atlas UI, where I needed to manually change each page layout for 100+ pages.

What would be nice?

1. A wizard to change the layouts of all pages, where you get a list of all current layouts in use and for each/all/multiple of those you can select the new layout

2. Multi-select a couple of pages, add an option in the context menu to select a layout for all the selected pages