LFGSS and Microcosm shutting down 16th March 2025 (the day before the Online Safety Act is enforced)

Perhaps joint liability as a condition for all members of the forum is the solution. Signing a binding agreement on joining of the forum for amny incidence which would transgress the legislation. Not only does it mitigate Velocio of the risk but also keeps everyone on their toes knowing that they are responsible for everything that they post.

Not really. Even with this in place it does nothing to stop a troll from joining, giving false information, signing whatever binding agreement is necessary to be able to post, and then doing everything they can to cause the site to fall foul of the act causing maximum hassle for everyone involved (including Velocio).

Avoiding the "giving false information" point would require everyone to have to submit significant documentation to prove their identity, and this would need to be held somewhere, which is unworkable for many other reasons.

That, as I understand it, is the biggest concern. It is very little work for someone to do something pretty much anonymously that can cause an imperial fuckton of problems for the person/people running the site.

(This has always been the case, but the OSA makes the possible consequences several orders of magnitude larger.)