We are happy to tell you that in 3.5.0 version we made it possible to manage and schedule Issues under the Epics on the roadmap!
Open and edit Issues under the Epics on the sidebar
You can now view and edit the details of Issues under the Epics by clicking on them the same way, as you can do it with the Epic Issues.
Schedule Issues under the Epics on the sidebar
You can schedule these Issues the same way as Epics. Simply move them with drag and drop or resize them as you wish.
All information that is displayed for the Epics on teh roadmap with the view settings are availbale for these Issues as well.
Save and restore Issues with the baseline option
The recently introduced baseline feature will save and restore the schedule of the Issues under the Epics.