I’m a native English speaker, but the meaning of the English translation “Let it hang.” is not clear to me without context. “Let it hang” in English can mean so many different things, like leave a physical object hanging, leave an internet connection request or some software request to timeout. Most often though “let it hang” is associated with “let it hang out” which has a different meaning, i.e. let the truth be revealed. The usage here is possible, but uncommon.
I can connect the dots after-the-fact for what this means, but I think this translation is inappropriate for teaching the word “unentschieden”. I think it would be better here to have a more literal translation “Leave it undecided.”