I assume for aggressive blocking the only prefix size will change. What is a /32 for IPv4 might become a /64 or smaller for IPv6.
Shouldn't blocking v6 also be based on /32 if you want the attacker's cost to be the same?
Larger. A /56 and get multiple hits from nearby /56s and you block the /48.
Shouldn't blocking v6 also be based on /32 if you want the attacker's cost to be the same?