I'd like this scenario: All unregistered users get the CAPTCHA on edit, registered users only get it if they add a URL, and autoconfirmed users never get it.
This could be a popular setup if it were possible with the current customization options.
Version: master
Severity: enhancement
Recommendation:
Forget the binary skip or no-skip approach and have it work just like user rights:
$wgCaptchaTriggers['*']['edit'] = true;
$wgCaptchaTriggers['user']['edit'] = false;
$wgCaptchaTriggers['user']['addurl'] = true;
$wgCaptchaTriggers['autoconfirmed']['addurl'] = false;
This would allow people to customize it however they want.