I like this feature. But I would also like the option to create a new layout from a blank layout. I know I could just open a "sample" as well. I'd also like to be able to "save current layout" and have it update, rather than having to save it under a new name. for myself, I'm the only person using my layout.
Maybe there's a warning option if it's shared by several people, like:

"do you want to update the layout within the list only, or do you want it to update all users with this layout?". Something like that.