First, there are things that I agree with and others that I don't agree with. Work organization methodologies are a first approach to real problems but they are not the final solution. The metrics that I present are nothing more than an approach from which to face the problem and have data to make better decisions.
1. Activity Days not only shows the modified lines or the affected units. It generates a report of all the activity in that sprint if you click on the blue button and it shows you all the tasks performed in that sprint with an associated impact value.
2. Impact is not associated with risk at any time, it is associated with an algorithm that determines among other things the level of dependencies affected, message of the commit or lines affected by a commit.
3. Code churn is nothing more than an approximation to know when there has been more flow of changes in a specific repository.
4. The flow of all work is something we are working on in scope.ink for the next releases. We will integrate exactly what you have written: how the entire flow of a task works from the moment it opens until it closes and how the work is connected between the software engineers. In any case, software factories help them know the average time of tasks to make better cost projections.
Thank you for your contribution knight and we keep in touch!