I don’t actually know how it works so I’ll just assert my understanding and if I’m wrong hopefully someone knowledgeable shows up and teaches us both something.
From what I understand, in your described setup, only sh.itjustworks keeps track of the votes on “awesomecommunity”. Other instances, e.g. lemmy.world, get the count from the community’s home server. Other instances send their votes and comments to the home server, which is responsible for keeping track of everything.
I’m confident at least 20% of that is accurate, give or take 25%.