I started working on building layouts tonight, but ran into some trouble. I tried converting the layouts we use from the Page Creation Portal and found that several things were breaking when i switched from Source mode to Visual mode on the editor.
I actually built the Song layout since that was one of the more simple templates we have. I created input boxes for all of the infobox variables and it seemed to be working okay. Then I went in to convert the sections over to paragraph input boxes, but the layout builder didn't seem to like that. Since I was working in source mode only, I enabled the Visual editor and eventually got the paragraph boxes working. I saved it and moved on to the Episode layout.
The Episode layout was a much trickier proposition. It had a lot of hidden comments on it that didn't allow me to use the visual editor on it. And I needed it to create the paragraph boxes. After seeking out help from the Wikia support chat in IRC, I found out that there are lots more issues with Layout Builder that makes it unsuitable for us to use at this time.
For instance, once a page is created by layout builder, it can only be edited by answering questions from the layout form. It's no longer editable in Source Mode. What this means is that you can't expand an article to include other headings once you've built a page with a layout. At least this is the information I've gotten from the chat room. I'll keep everyone posted as I investigate further.