This is generally about maintaining and tidying up projects.
In Nodered, you can use the magnifying glass in the node list, e.g., for subflows, to see which flows they are used in and delete old unused ones. The connections can also be traced in the editor for normal link-in and link-out nodes.
It would be very helpful if there were also a way to check the link calls to see if and where they are used in order to remove unused ones and optimize the system.
And it would be perfect if you could jump to the link call using a special key and double-clicking (equivalent to the subflows).
This may be common knowledge, and itās not as elegant as solutions others have come up with, but you can search by the link-in node ID to find link nodes referencing it. The link-in node ID is under the info section on the right; if no search results appear other than the link-in node, itās unused.
Give the link in nodes names, then they are easier to find when configuring the link call node and easier to search for. I also expand the node in the flow so that the name is shown.