Change and diff previews vs a specified commit, not the head commit?

I find the VCS feature of marking with bars in the left gutter changed sections of the open file, and the ability to quickly see the diff with the commited version hugely useful. Unfortunately, this leads to me to commit much to rarely, in order to not lose that information. Is there a way to change the behaviour to compare the file with its version in a specified commit, not the last one? I would like to have this functionality work with the commit from which the current branch branched off, so I see which files were changed as a part of the task I am currently working on, be able to easily revert these changes not on file level, but individual patch sections.

I know that I can just request IntelliJ to show me a diff with any version, but that:

1.   Shows the diff of the whole file, not just changed lines,
2.  Opens a new modal window,
3. Most importantly, I can't say which files are changed without opening the git history window; I have to specifically look for the information, it isn't provided to me automatically.

Is there a plugin which does that? Should I ask about it in the plugin forum instead?