There are quite a few improvement that can be made to the stories functionality in the mendix app platform.
1. Being able to tag a person to a story, so its possible to see who is responsible/going to do it.
2. Being able to make "epics", its very helpful if you could put specific story under a main subject (example: The subject Backend has all the story which have something to do with the backend in it.
3. Making the controls bar stick to the top of the screen (the backlog is all the way down and if you want to move certain story somewhere else you have to scroll all the way up first or drag them which is very slow if you have alot of stories.
4. General usability like having to click on a story/task/sprint to be able to make a new underlying story/task.
There are probably a few other small improvement that would make the stories alot better (comment if you have any). Currently we lose most time during a retrospective on putting in/ changing stories. There are great tools out there that work great aswell for tracking stories but that would make the whole scrum integration from mendix a waste. I think it would be a good idea to have another look at the stories tab.