So I have been using Azure DevOps for the past couple of years and have now started using JIRA again. (I have used JIRA for several years prior to Azure DevOps). Having used Azure DevOps, I have a few questions and am wondering if the below features are available on JIRA. Haven't been able to figure them yet:
1. On Azure DevOps, I see all the test cases and subtasks on the board collapsed as icons which can be expanded. Is there a feature like that on JIRA?

2. I've been playing with Advanced Roadmaps to create something similar to Azure DevOps delivery plans. I have created a plan. created shared teams but don't seem to be able to add them as a row or swimlane similar to how it gets displayed on delivery plans. I've found this very useful because you can create a board at feature level and each team's feature will be displayed with dependencies etc.

3. I know you can customise the hierarchies in advanced roadmaps. However, in all videos and posts I've seen, everyone is adding level above Epics. I personally don't find that useful. The best structure for this hierarchy to me is Epics > Feature > Stories > Tasks. Wondering if anyone knows a way to do that?