I would like to understand if you are referring to an indication for attachments only or also to an indication for linked user story and defects?
Assuming the latest, can you share which kind of indication will be helpful for your use cases? Is it only indicating the fact that there are linked user stories or defects? Do you see a use case in which more details about the linked entities is needed in the grid level, e.g. the highest severity of the defects that are linked to a user story?