I do remember the posts about the problem you had.you will need two more axle bearings to prevent the "VW" syndrome on the rear tires.
They will tend to tilt inward at the top. been there.
In my case, the frame is engineered differently, which eliminates that problem.
I have a cross member in the back that is doubled in the center, .....very strong.
Additional bracing yet to be installed, which will reduce/eliminate frame flex in that area.
Also notice that the hubs are quite substantial, and are up against the pillow block,
further reducing any chance of bending from normal driving conditions.
With the newly made, body bottom frame, that will bolt to the chassis frame,
adding additional strength, I can't fathom how I would ever have the same problem.
I may add an additional pillow block in the center area, for the drive,
but I'm leaving that, until I know how much room, I will have left after the body is finished.
I have allowed +/- 12" -18 " behind the seat, for batteries and drive components.
Seat bottom cavity design comes into play as well, thus additional room if needed.