Rally to Jira Export, including Test Cases

We're moving from Rally to Jira and have the export set up so we can move projects from Rally to Jira quite well.  Any fields not mapped are put straight in the description field.  We are using this method - https://help.rallydev.com/jira-installation-user-guide

However, we now have stories/defects that include test cases.  I haven't seen or used the test case functionality in Jira.  It looks like there are add-ons to create this functionality.

My question is, do you have any advice for either using Jira as-is for test case functionality (e.g. modifying workflow) and exporting those test cases from Rally to Jira?  Or, using an add-on, and is it possible to export from Rally to Jira for the add-ons?  Is there a recommended add-on for test cases - particularly one thats similar to Rally?