I don't know if I agree with you. Your idea of following a topic over all communities is a solid one, for sure. Not sure I would agree with a comment being posted across all. Maybe an option for cross-posting, should one wish? How would you deal with the replies though, like certainly that all couldn't be cross posted, could it?. I just think it would get too complicated in a hurry, that's all. I like your ingenuity, anyways.