The angle or slope at the tail of a floating bridge soundboard very much affects the sound by applying more pressure on the bridge (than a shallow
angle). This is only on a floating bridge oud. The original 1956 Bashir design Fadel Hussein oud actually had a bent tail section like a mandolin,
but this was abandoned for a gradually sloping shape. FYI every feature of the soundboard affects the sound, one way or another.