Currently only one resolving items is allowed per issue.
Most of the time we have more then one action to address an issue, so limit of "1" forces us to create weird workarounds such us creating a resolving task, with many subtasks, or a task with many issues, but then reporting on progress becomes cumbersome.
If issue could have many resolving items, it would become easier to report by filtering items that have "this resolves" relationship defined and group by it.