This discussion makes me wish I could remember half of what my college dynamics prof said. Heck, it makes me wish I could have understood half of what my college dynamics prof said.
If you design overbanked turns just right, the forces can be very low, in fact, lower than you would have in a standard banked turn. The only problem is they are in a strange direction.
That reminds me of a certain banked turning hill on Boss that I swore would give latteral air to the left and the curve was to the right and banked that way. We actually got air but dropped to the right.