readme

README.md

@@ -71,6 +71,7 @@ This was decided for a few reasons:
 1. Routing configs should probably have a far lower cache than certs
 2. Fetching cert and routing config at the same time would guarantee that we use at least two TCP packets in the response, where a routing config can often fit into just one
 3. They should be stored separately in the control plane, so it doesn't make sense if we need to do 2 lookups every time we want to refresh the routing config cache
+4. It helps for the case of needing to bulk-issue certificates (where multiple domains are included in the same cert)
 
 This is where the `CONCURRENT_FETCH_ROUTING_CONFIG` setting comes in. Because certs are cached more aggressively, and you always need to have both the cert and routing config to answer a request, when we are filling the cert cache we asynchronously fill the routing config cache in the background.