There is an experimental Convertigo project to backup all databases of a Convertigo Cloud Server at once, that can also be scheduled, it is not officially supported.
Deploy the following project to your Convertigo CLoud Server:
Create a new sequence job from the backup_cdb project, pointing to the launcher sequence, fille the server variable with the name of the Convertigo Cloud server holding the CouchDB (my_server.convertigo.net):
This will create a folder <YYYYMMDD>_<Server_name> containing all the CouchDB databases as .gz archives.
Or use CouchDB replication to back up the data to another CouchDB installation.