Re: How is a Warre functionally any different than a foundationless Lang?
As you already mentioned, Warre hives have a quilt box. you could make a quilt box for a Lang, but that is not how they were traditionally designed.
Warre boxes are much smaller than Lang boxes. and they are intended to be nadired (placed below the stack) rather than supered (placed on top of the stack).
Abbe Warre did tell in his book that he provided directions to build frames for use in the hives or it could be used with just top bars. He personally preferred using only top bars as he did not recommend moving the hives as a migratory pollinator now would move hives. He feels that using top bars gives the bees the maximum capacity or space to draw comb out as they will. With frames, they have less space to draw comb.
The biggest idea of Warre hives is that one is encouraged to take a minimalist intervention approach and not open the hive unless it is for specific purposes, such as preparing in the Spring, harvesting in the Fall or rectifying some major problem throughout the season as based on exterior observations. (H Storch's book "At the Hive Entrance" is a very good companion to making such determinations based on external observations)
Abbe Emile Warre intended the hive to be used by the 'average" person who did not want to or was able to tend to bees on a daily or fairly consistent basis. It is designed to achieve a large honey harvest with minimal opening or "working" of the hive. Much of his explanation in his book for the methodology is based very much on biological behaviors, traits and similarities to 'natural hive" activities much as possible.
Some have described it as akin to robbing a hive in a tree, made easy.
Essentially, the bees live in the boxes much as they would un interrupted in a tree hive and because the boxes have removable top bars and are separate boxes themselves, it is that much easier to harvest honey. The harvester need only take those boxes of honey that are only honey and leave boxes on the hive that are mixture of honey and brood.
(this usually leaves 2 to 3 boxes on the hive over the winter in which they continue to work down into the bottom box and backfill the top box(es) to live off during winter.)
No, I am NOT a bee "Keeper". Anything I post is just my opinion. Take it easy and think for yourself.