Deleted Characters Being Reviewed

that's just as bad.

Not nearly.
First of all, by changing the timeframe from seven months to 3 weeks, you're already saving at least 90% of the innocents from any harm at all.
Second, by setting up the automated checks, unbans should happen fairly quickly. (I'd have put these checks in the initial ban script, but Nexon is known for a "Kill them all, God will know His own" attitude. Also I've heard horrible things about their database efficiency. Checking those things for every single skill-getter in the time-frame, when the vast majority of them are, in fact, hack-UAs, would lengthen the maintenance unnecessarily.) The people who would need to submit screen-prints and have a human examine their case are only those who created a UA and deleted its KoC within the past few weeks. I seriously doubt there are more than a handful of them.

And of course, the most important bit, is banning instead of deleting. Whoever thought up the brilliant notion of deleting, especially coupled with the seven-month timeframe, is... *facepalm*