I think a badge for frequent critiques could be beneficial. As in something awarded to people who regularly provide constructive and useful criticisms and suggestions on how to improve their art (either in the forums or in comments of images).
Of course, that would be a very discretionary badge, as it’d be almost impossible to set a measurable criteria for such a thing. Instead it’d be just a thing where people would either have to be nominated, or a mod would have to notice someone providing useful critique, and then there’d have to be some judgement on if the critique is good, valid, and respectful or not. But it could also encourage people to contribute feedback as well.