I might be mistaken, but I wouldn't think it would be that many classes. If I remember correctly, most blocks just use the standard 0 render id, which wouldn't require a code change. As for the ones that do, I thought most of those class files already had edits, and a simple removing of a method and adding a line to the constructor wouldn't be that much to ask.
Of course, I know I can't argue this, but I don't really understand where the difficulty lies. I can take a look myself at the code and its changes to see what it might take to add it and upkeep it.