How much effort would it be for them to create a new one and do it again?

Minimal, but it is the domain that gets blocked so the attacker would still need to purchase a new domain.

StarTrek.website saw 4 approved registrations in the past day, and we typically get about 1/day too.

Stories like this make me very happy to hear. When I heard the /r/StarTrek and Daystrom mods talking about joining Lemmy I’d thought bringing their reputation for positivity and tolerance to a Trek-themed instance could provide a familiar and comfortable jumping-off point for users unsure about the broader Fediverse.