Your comments

I also really would want this feature.
I do a lot of single commits and often want to see the summary of these commits.
Also I use a external Diff tool and therefore I want to have the {rightLocalFile} in the right window to be able to direct modify the file on the filesystem. This allows me to be able to fix some things from the last commits, because the sum of all changes has to be correct and coherent.
Workaround as for now:
- Stage all files, so index is more or less the working tree
- Create a batch script which checks if a right file to compare is a file from the index and then instead of using {rightFile} use the {rightLocalFile} for the external diff tool (open the diff tool in the batch file)

Sadly this workflow is not as good as with tortoise git...