Metadata for JIRA should be Data Center ready (it’s stateless). But I’m not sure about my project update listener (com.osoboo.jira.metadata.internal.ProjectUpdatedEventListener.
It seems that here is only a Data Center plugin validator available for confluence (https://developer.atlassian.com/confdev/development-resources/confluence-developer-faq/how-do-i-ensure-my-add-on-works-properly-in-a-cluster/confluence-data-center-plugin-validator) and the test-setup looks a bit time consuming (https://developer.atlassian.com/jiradev/jira-platform/jira-data-center/plugin-guide-to-jira-high-availability-and-clustering/configuring-a-jira-cluster-for-plugin-development).
I can’t tell if and when I’ll set the mark. The update from JIRA 7.0 to JIRA 7.1 was to time consuming.
Workaround: You can fork my repo (https://bitbucket.org/aspall/jira-metadata-plugin) and set the data-center-mark in your own build.