As a sysop, I would like to whitelist at MediaWiki:Captcha-addurl-whitelist any god URLs which might be added as sources by new users, so that they can reference articles without having to solve a CAPTCHA. For this, I would need to know which sites users attempt to add. It would also be useful to have a way to get stats on how often users attempt to edit an article and give up after receiving a CAPTCHA.
For this, the extension would have to provide a log of such edits (e.g. as in abuse filter, which allow us to see each filtered edit to check if it was a false positive, and maybe contact the user, or reinsert the valid content).
A workaround would be to implement the request from T20110: Allow AbuseFilter to force the user to solve a captcha.