it seems from a very brief search that likes and dislikes (see link below, i assume they translate to up and down votes) are the extent of what is available so a more nuanced slashdot or steam review type rating is unlikely to be viable.

in any case the ability to upvote and downvote feels like a core differentiating feature to this kind of forum and inbetween measures are unsatisfactory. upvote and downvote anything you like, and everyone can see you doing so. at least it may be possible in a future version to allow or disallow voting behaviours on a community rather than instance basis?

www.w3.org/wiki/ActivityPub/Primer/Like_activity