The comments are time tracking makes sense. But not sure what is the potential poison. I think the tool should support getting this data so that the team can use this data to self organize or for a team of junior engineers, Scrum Master can help organize or distribute the tasks.
Actual hours spent vs estimated hours - The tool should support it, but its usage left to the team. A team member may use it to get better and also might be plan and organize better.
Also please explain why this is deterimental.