I believe the idea behind BB-7618 was to move all such information to the maintenance epic of each client (which is usually the correct place to log time). The problem is discoverability (which has been a recurring issue since we migrated from documentation → Monday → CRM → Jira). A central place (linked in the alerts channel) with at least links to these epics, URLs to the instances (for quick searching when there is only the URL in the alert), and contact people could be a good start here.
Also, it would probably be a good idea to review the epics to ensure they include sufficient details about the client’s instances. Here are my maintenance epics: BB-352 + BB-3154.