I'm not a fan of votes being so public either. It almost seems to guarantee potential harassment as the platform grows. Hiding the "more" button on kbin only kicks the can down the road if this is a natural part of federating instances. The problem just comes back once a single instance makes the information available.
Without a change to the protocol, I think we're stuck with education. Maximize the awareness from users that votes behave differently here, and are entirely public.
People have moved from reddit expecting a 1:1 copy of the features, and for the most part it delivers. The comment system has all of the friendliness of upvoting, but if you click the arrows you're stuck committing to more of a retweet. This could really bite users who reuse their account name everywhere, and those that use their real name online.
People getting started should learn about this as soon as possible and really consider how it will affect them. Do they really want to engage with the NSFW content, or maybe a new username is in order?
It would be horrible if users were to arrive with the wrong impression, have a negative experience and regret showing up at all.