Is there a list of servers that must be queried for verification? How are they given to provide high availability in different bounderies?
Is there some way of getting a guarantee that SSL certifcates and the ACME clients can be usable in other countries, comply with local lawss and be generally available?
Sensitivity to encryption, and many issues recently with major CA distrusted, it is import that LetsEncrypt have a way to get around or be resilient to problems. Even today, major CA servers are being filtered or being taken down on short notice.