Agree, we have some time in sprints to do whatever we want, and then you finally can fix those minor annoyances that are probably the users annoyance too. But in general I think more time should be there reserved for it. It's now once in x sprints.

When working on my own apps it's really obvious that non focused time leads to lots of improvements. Instead of only the business wishes. In that regard it seems that the potential of a dev is a bit diminished when you don't have time to do things according to your own priorities.