I released a new version of the git-forensics plugin recently.
You now can see some statistics from the commits of the current build (added and deleted lines, changed files). On the main branch the statistics are computed between the current and the previous build. On development or PR branches the statistics include all commits of this branch (or PR) that are not part of the main branch.
Here is a screenshot of the build summary:
Next plan is to add a portlet for the pull request monitoring plugin.
If this is helpful I can also add charts that show the trend over several builds, in the same style as the trends of the Git miner step: