The OP on Reddit does suggest making sure it is fully mixed/hydrated before starting the kneading/rolling process, but says it tends to eliminate dry pockets over time. I was more concerned that the lid might pop off, some Cambro-style containers don't have a very tight seal. It's a very slow roll, slower than 1 RPM (the video is sped up), so gravity would tend to pull it down as it rolls around.
I'm not sure I've got the woodshop skills to make one of these, though. Maybe someone will do a kickstarter to make these. I'm also not sure how often I'd want to make more than 4 pounds of dough, which is about the upper limit on my 4.5Q KA.