This is why I think heavy duty semi float axles are an oxymoron.
Here is a visual aid from fourwheeler magazine, that I drew on:
You can see the rub marks from where the bearing that supports the entire rear axle weight rides on the axle shaft.
The wider rub marks to the out side, closer to the hub is where the oil seal rides, the thinner more even rub mark further down the axle is where the bearings ride.
With full float the hub and the weight of the vehicle rides on the axle's tube housing structure. All the axle has to do in a full float application is drive the wheel. (this is why I switched to a 3/4 ton suburban and full float axle)
So you want to put all the drive torque, the weight of the rear of the vehicle, thermal stress from the rear brake and the moment of inertia from the off set all on one point?
On paper it looks like a disaster waiting to happen.
With all the stupid stuff people do to half ton trucks and fact that semi float axles are not snapping the hubs off all over the place is a miracle.