Federation shenanigans would be my guess. If you were on instance B and moderating instance A then instance B admins would have control of your account instead of instance A admins. So if for some reason instance B admins decide to ban that user then they are prevented from moderating for instance A.
Just out of curiosity, what's the advantage to them having their account on the same Instance as the community?
Federation shenanigans would be my guess. If you were on instance B and moderating instance A then instance B admins would have control of your account instead of instance A admins. So if for some reason instance B admins decide to ban that user then they are prevented from moderating for instance A.
Or more commonly, if your account is on instance B and instance B goes down, good luck moderating insurance A