It's been awhile since I had to deal with ocsp breakage, but if it breaks due to an ocsp server down, doesn't that mean the browser or web server is misconfigured? Of course, if browsers are misconfigured out of the box, that doesn't help at all...
It wasn't as simple as the ocsp server being down. It was returning bad request (http 400) responses. When the good responses expired from caches, the bad responses started going out and breakage started spreading. LE detailed this in their postmortem which I linked.
