Why though? If the user is not breaking your rules, what reason do you have to know that?
I just told you, having users that are reported a lot is a defederation risk. Also the reports may actually indicate problems that also break instance wide rules and you’d never know.
feddit.dk is another instance with huge amount of isolation with 533 instances defederated.
I don’t think it’s very isolated actually. I implore you to take a look at the instances on my block list. It’s not instances you’d want to have an influence on votes. Basically all “normal” lemmy instances are not denylisted.