As backup it's an excellent idea! I know world changes have been used a lot before as prison breaks, so it would at least be some kind of precaution, if fallible.

...It's kind of a shame we don't have a character like Kurapica from Hunter x Hunter who can put a seal on someone where if they break its terms, they die. That sort of precaution would let convicted criminals run as free as they like, but with immediate consequences if they break their word. And it'd still give them leeway for finding a way to avoid the letter of the law.

(Or we might and I just don't know their canon well enough....)