I have been using Codex extensively to fix crashes. Usually when I get an obscure crash I go “well there goes my afternoon”. These days, I paste the stack trace into codex and go “fix this”, and it does a remarkable job at finding clues I miss, and to find the root causes.
It doesn’t always work, but it has a very solid hit rate. What seemed like a daunting uphill mountain of despair is now a quick sweeping job.