so that might be a problem currently because you would be relying on those 40 for moderation, now if you only read your feed then its not an issue as those 40 would only be in it

i have discussed and it will come we need multiple feeds or ranking follows etc, so you might follow 500 people and uprank the 40 you want to read only into another feed, while having good antispam if you browse the global feed from the 500