When working with multiple files, or consolidating a multi-file solution, getting layouts from one file to another is very tedious, especially if it involves several parts, like with reports. The ability to copy and paste, or import layouts from one file to another would be a huge time saver. The UI could be just like it is with copying scripts, custom functions, etc. And it could be a developer-only feature and another way to differentiate FMPA from FMP.
If we paste or import a layout before the required TOs are there, we could deal with fixing the relationship references, or better yet offer a dialog that says: the TO "<TO_name>" is missing. Please choose a new TO… pick from the list or cancel.