as it could easily create a sort of positive feedback loop, where one super poster type person is just ... always on top.

I am not a member of this instance, and I am so new to Lemmy that I'm still in the process of grasping instances and federating and so on, so feel free to take everything I say here with some big grains of salt. But to add to this, rather than just a person, I think this could wind up emphasizing a trope-ic sort of personality rather than just enshrineing an individual poster, and push a community towards an "ideal poster," which, if everyone competes for is going to make things very samey and eventuallty an echo chamber. Though, I dunno, maybe that's what you want. Or not. Or maybe the instance is too broad in topics for that to happen, and this is a total non-issue. I have zero idea about this instance. Big grains of salt and all that.