We (researchers for UC Santa Barbara) are developing a tool that will help in propagating patches.
Would you be interested in a tool, which identifies patches that could be imported with a minimal or rather no testing?
E.g. Security patches, you can import security patches as they usually do not affect the functionality.
This tool would use only old source file and the new source file!! No commit messages, no build setup, nothing!!
Something like: git saferebase?
This tool could be used to import patches from the main source branch to your branch without worrying about testing them.
You can also use this tool as a patch monitor, which monitors all commits to a repository and inform you about patches that do not affect the functionality or otherwise safe patches.