Which would allow to coordinate issues by multiple components and features across e.g. a Jakarta EE release. The same board is also available inside each project.
A nice feature close to JIRA links is a "requires" tag allowing to define some issues as show-stoppers for others and vice versa.
Any other similar tools you would recommend?
While the top level project is probably something the Platform project may find useful, other tools and "Kanban" extensions are probably up to individual projects like using Travis-CI or other tools if they find them helpful to their goals.
If there are other alternatives that projects already use, please let us know, otherwise it may be more for individual project lists to discuss what may be useful.