I tied mine into the bearing flange, but just the edge.
The diff that came out of the car wasn't quite as short, it wasn't backbraced, and it was easily identifiable as "BOW" shaped. Even from a distance...

This is the new diff, I'm wondering if I should have brought the backbrace out even further?

I dont know, it looks fairly short(the housing width)
so it would deflex less. I went out on to the flange
just short of the wall so I could weld there