Maik Koster has created a really good tool that monitors/ keeps backup of task sequence changes
expanding from this it may be possible to mark groups of your task sequences as modules. So say when a task sequence changes the script would then record the xml changes of that module group and replace in all task sequences where it is used. It would be perfect for the apply driver steps.
I haven’t really worked it all out as I don’t have many task sequences for it to be super useful and it would be a bit to hacky. I hope Microsoft can implement modules and version control in the next release of ConfigMgr.