PARTS of this POST EDITED BY BEEMASTER - Jeff I'll write you and let you know why if you don't see the need for editing.
[...with foundationless the bees festoon all the way across the frame and work in unison...]
This is my observation too. Its as though the team work is cut in half by any prestructured foundation.
But you may desire plastic foundation in the honey area for strength, structure, and ease of processing.
Natural combs can be difficult to have drawn straight, and nearly never are they drawn with uniform cell sizes, and can blow out will extracting. The benefits of natural cell is mostly appreciated in the brood area. That's a deeper subject that should be (already is) covered in another thread. Uniform cell patterns also aid in structural intregrity.
You can create barriers using capped frames of honey that inhibit (but not necessarily prevent) the queen from laying in upper boxes. He also adopts the doctorine that all frames are fair game for use throughout the hive. Well, some people prefer to reserve certain combs for honey only production as they feel it produces cleaner or lesser darkened honey. I also like dedicated frames because it allows for removal of honey by variety (as flowers bloom). Frames scattered throughout the hive most honestly has to label its honey has generically wild flower. Its all a matter of preference and intent.