Re: Maybe this is another crazy idea.
It's about foundation. Given a box on top with foundation, the bees will work up into it faster than they would into a box of foundation below.
But Warré hives are foundationless, so the bees are reluctant to move into an empty box put on top they would have to start comb building from the top bars quite far from the rest of the cluster. So Warré people add the box underneath so the top bars are right under and next to the cluster so the bees can more easily work into it.
However there is a drawback to supering under the hive. Bees prefer to store honey at the top. So in a Warré, with new boxes added underneath, the brood nest is initially at the top of the hive. When the nectar flow starts, as brood cells hatch, the bees fill the cells with honey, and the queen is forced to lay eggs lower in the hive, so over time, the brood nest moves down. So the bees only have room to store so much honey, as they are waiting for larvae to hatch and the brood nest to move down. If there is a heavy flow, and the brood area is blocking honey storage, the bees simply don't collect it.
In normal lang practise of adding boxes on top there are no such restrictions, the bees are free to store limitless amounts of honey, long as the beekeeper keeps adding boxes.
Abbé Ēmile Warré himself, developed his hive in an area that's been described as not having strong honey flows, and in that situation it worked OK. However the Warré hive is still 1/2 the size of a lang, which is another limiting factor. Abbé Ēmile Warré developed his hive for "the people", who he saw as largely not wanting to mess with building frames and using comb foundation, so developed this more simple, stackable top bar hive.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).