For a cluster of machines I have stored a lot of identical bookmarks. All servers are equal, but only changes the address (IP). And inside the connections I have configured a lot of advanced parameters.
So my proposal is to support "empty" or "pattern" addresses. Or most simple, a simple check for "request for the Host name" when opening the connection (the stored value is then shown, but you can change it before stablishing the connection).
With this improvement you can store bookmarks like: "*.cluster.net" and select the target machine when connecting.