I improved a similar issue by writing custom instructions for copilot that give it enough context to do PR reviews that are only 30% BS.

I asked other team members to run my custom instructions to perform a review with copilot before they submit...

Of course no one is doing it. It looks like the PRs I get are still straight from copilot. So I tend to run my review prompt. Cut out the 30% BS issues it "finds" and the rest is good.