Right now if you make a change to a layer that's shipped inside the eSDK (say you do devtool modify on a recipe in OE-Core) and then you want to submit those changes back in the form of a patch, or even share them with someone else, then it's quite difficult to do so because for a start the layers don't have their git trees included. This was intentional to try to reduce the size of the SDK installer, but it may be that we should revisit that, provide a way to make it optional, create a fresh git repository for all of the layers, or something else so that we can track such changes.