Currently we are on Standard plan. But looking to have the only feature of creating our custom hierarchy as per our line of business.
The premium plan is expensive for us right now and even 3rd party applications is a NO at this time.
We tried using Sub tasks as level 3 but it has a lot of restrictions/complications like moving subtask to a new sprint(which is not possible), estimate of a subtask in total sprint(which is not a recommended approach by JIRA/Atlassian)
So looking out for something