I actually like that Falling Devil doesn't affect falling in the physical sense, but also in the conceptual sense, such as falling after failing to meet up your own expectations or falling after experiencing a failure.
Although this now makes me feel like Denji beating her will not be as satisfying as Asa beating her, since Asa is still filled with self-loathing that she needs to really let go to grow as a person and her beating the personification of falling seems to be key here.