The upper balcony of Ember Keep is made with an ex_imp_keep_01 which has been scaled ×1.75. That makes the battlements too high to see over, so someone used six scaled-up benches to cobble a sort of bleachers/staircase thing. Once this asset is merged, it should be used to fix this issue more elegantly. The load door on the balcony is perfectly aligned with the interior of the keep, so the way to resolve this is to add the new floor piece in the same position and scale as the current floor, then slide the ex_imp_keep_01 downwards a bit.