To my knowledge it doesn't consume anywhere near as much as a running NN node does. Remember that the Linux superblock contract forwarding involves Windows nodes passing data in the form of compressed contract zips (<50 KB) to Linux nodes which then stake using that hash. The overhead should be rather minimal.
To your other point, there will be a flag in the config file that allows users to disable the feature if they desire.
Cool thanks, Linux users might be on older/low power kit