How about expanding the n-th degree follows to the relay, too? If the author isn't followed by anybody of the relay maintainer's n-th follows, reject their event.
#[4] commented about ephemeral authors being bad. Yes, they are. They are indistiguishable from spammers.
We've been lucky so far with spam. I think how well relays deal with spam will be one way people choose between them. Not convinced this is intentional spam as it's too easy to stop...It'd be better if they changed the pubkey on each event - a relay would still be able to have ip based rules... though ip based rule might hit any mirroring that goes on as the mirroring service is likely to get banned.
