In a sense this sounds like putting gratuitous work burden on your own mod team for something folks will never see anyway - no one is going to boost it onto your instance or follow those accounts anyway, right?
Unfortunately, what happens is that someone you (or someone else on the instance) follow on a low-moderation instance will reply to the hate-speech posts denouncing or debating with them. Then the hate speech gets federated to your instance and shown as soon as you click the response trying to see what it was about.
Preemptively removing these posts is really the only way to avoid that.