To me, the core problem with star ratings on itch.io is that very few people actually rate things, so you do not get decent sample sizes and thus a single bad faith review can heavily distort the end result.
(I got two ratings on my game over 10k views and 400 downloads. One of them was genuine, the other one was a retaliatory bad rating by some spammer who didn't like my review of their slop.)
If review counts were higher, individual retaliatory reviews would have far less impact than they do. With review counts being as they are, review scores are functionally useless, with or without your mechanism for filtering out bad faith reviews. Your mechanism also couldn't possibly counteract brigading - where bad faith reviews may outnumber genuine ones - which is unfortunately a real problem that marginalized creators face.
So while I appreciate your effort, I think a better approach would be to just hide the review score on store pages until there's at least X individual reviews, with a relatively high X. Even then, this is a technological solution to a social problem and those tend to be... not great.
Game creators who want to opt out of this nonsense can just disallow ratings for their product.