List all issues that are mentioned in a ticket
I would find it helpful to get a list of all mentioned issues in a ticket. This is somewhat similar to #5453, but I could imagine that those issues do not get into the list of related issues, rather it could be a separate (visually collapsed) list in the head area of the issue. This would be similar to Stackoverflow where the side menu also contains a list of related questions.
One can then get a quick overview of related issues without the necessity that someone has explicitly and manually declared issues being related.