There is a disable button on the web interface[1] which allows you to either disable it permanently, or for a specific amount of time. Of course, client devices need to clear their DNS cache, too, in order for this to work properly, but at the moment there is no way of automating that.

There are also other tools to help with blacklisted domains that cause issues/site breakages, such as a query log to identify them, and the ability to whitelist with ease!

[1] http://imgur.com/a/DlIeq

Is it? I'm sitting behind a similar DNS-level adblocker and the only thing that I've noticed broken from time to time is analytics.twitter.com (some external links in the Twitter app route through there, but not enough to annoy me). Or maybe I'm just avoiding all those blocker-blocking sites effectively.

Then they let the admin know. The admin then whitelists the site and no more problem.

There can't be that many of these situations.