As a followup to a question raised in community I would kindly like to ask you to consider implementing a similar feature to one you have in your Crucible product. When reviewing a pull request with multiple commits, allow to select a range of commits to show diffs of. 

In crucible, the UI looks like this: 

You can drag the red circles to select commit range to diff.

Also, showing comments on code if it is within commit range would be helpful too.