I really love the mosaic concept. I think it's indeed the missing piece for tiling on large displays. It's a kind of stack in usual tiling layouts, where all leftover windows are placed, but stacks tend to squeeze and deform windows, crippling many apps in the process. The mosaic approach can certainly avoid this issue, but it wastes some space (not ideal for small screens) and may not play well with big complex UIs(IDE, CAD, DAW, etc).
