I am trying to convert doc to pdf/a using jodconverter and libreoffice. Default configuration allows to generate only 1.4 or 1.5 format. The only official option I have found is to use a proprietary "Document transformation engine". I don't like it because you need a windows server and ms office.
I tried to rewrite the jodconverter library in (repository docker) /usr/local/tomcat/webapps/alfresco/WEB-INF/lib/alfresco-jodconverter-core-126.96.36.199.jar to put this config dynamically to (libreoffice docker) /tmp/.jodconverter_socket_host-127.0.0.1_port-8100/user/registrymodifications.xcu but it doesn't seem to have any effect.
Also try patch and OOoDirect approach from link below, butI cannot find the relevant configuration files (openoffice-document-formats.xml).