It’s vulnerable af. And I mean really, it’s as bad as Netscalers or Fortigate shit. Like https://www.bleepingcomputer.com/news/security/hackers-abuse-ipv6-networking-feature-to-hijack-software-updates/ or https://www.bleepingcomputer.com/news/security/hackers-abuse-ipv6-networking-feature-to-hijack-software-updates/
Problem is, yes it’s hard to implement but it’s even a lot harder to get it properly secured. Especially because few people are using it, and not securing it is worse than disabling it.