Hi, I'm not sure whether this has already been discussed.
I'd like to highlight that a layout editor project might have as a side outcome the production of a LaTeX class file, to be used even without LyX. That would make its scope & usefulness even broader. Something like I edit the page visually and/or editing params, and I get a .cls file, as well as a .layout file to be used within LyX, that uses the .cls file. Just my 2c, T.