Added some minimal operational notes

README.md

@@ -97,6 +97,19 @@ Certificates are uniquely identified by the *names* list. It is a
 syntax error to define multiple requests for the same certificate. It
 is also an error to define multiple requests with the same *path*.
 
+### Operational considerations
+
+Acmeserver tries hard to be nice to the ACME API, and as a result of
+that it's **not fast**. It's going to take its sweet time to do things
+to avoid overloading the API, going through the renewals one by one,
+and allowing for extensive retry times.
+
+It will get the certificates eventually if the validation mechanisms
+are set up correctly. And if they aren't, it will eventually fall back
+to attempting a verification once a day, so if you have an issue with
+validation and you resolve it, know that's the time it's going to take
+for the system to notice.
+
 ## Internals
 
 The purpose of this tool is to obtain certificate renewals from an