Currently, when dismissing a screen which houses InputAccessoryView, the InputAccessoryView slides down at a set (slow) speed. If the screen's transition is faster than the transition of the InputAccessoryView (usually the case) then the InputAccessoryView appears to float on the screen until its own transition completes. If the animations are different then the result is just bad UX.
The InputAccessoryView should support some sort of transition handling such as speed and type to help match different screen transitions. Fade, slide left, right, top, bottom and duration would be optimal options to support for wide use cases.