[wpietri]

I think the error here is a common but artificial distinction between "existing features" and "new features".

From the point of view of a well-run Agile team, there's just work to do. It all gets managed through the same process. One queue, one team.

In my last team, we created a rule that when you finished something, you'd just pull the next card at the top of the stack. You could ask for help as needed, but it was your job to see that card through to completion. That forced us to cross-train. Which was certainly fun. But it also really helped us to make better software. It was very consistent, both on the surface and under the hood.