Anyone who has been on SE for any length of time knows the bypass of copying the comment, deleting it, and reposting it. Yes, that puts our revised comment out of order, but that is often acceptable.
Given that option being available, does the time limit for comment editing really serve a useful purpose? If editing after that moved us to the end of the comments, as the workaround does, that would be no worse and is arguably less error-prone.
Meanwhile, the lock discourages fixing typos. That's a significant cost.
What problem is edit-locking intended to solve, and is this really the best way to solve it?
Feel free to close as duplicate of, e.g., Should we be allowed to edit comments?.