I am asking you to add support for LogicalDOC DMS like you already have for Alfresco.
LogicalDOC is an OpenSource DMS with a nice CMIS ATOMPUB implementation but when using the LibreOffice CMIS connector not all operations execture successfully.
Once installed, you can access to the CMIS server at http://localhost:8080/logicaldoc/service/cmis (username: admin, password: admin)
I can help you in setting up LogicalDOC and even install a LogicalDOC ready for you on a server accessible from the internet so you will not have o install LogicalDOC by your own.