He will probably never go for this. Anything that compromises the "free speech" ideal of KF (well, "free speech" as long as you don't @ him in chat on the wrong day, laugh at his chimpouts, be British, give him a "mad on the internet" rating, ...) is likely off the table.There are a couple of options that Joshua has.
Move his LLC to a European country with a loser pays provision. In short loser pays means that if you sue someone and you lose, you have to pay the other person's legal fees. However, a lot of these countries are also much tougher with defamation laws than the US. This translates into Josh losing some of his freedom of speech and making some significant changes to Kiwifarms
This I actually could see. If Null could find someone who he trusts, who he isn't going to get pissed at/isn't going to piss off in a matter of weeks, and has enough likability/trustworthiness that both Null and the disputing party can expect this person to carry out mediation/arbitration without problematic behavior (i.e. sperging out at them, leaking discussions/proceedings on KF or splinter sites, etc.), it just might work. This, of course, will require a healthy dose ofA binding arbitration/mediation clause. If you sign up for an account with KF you agree to settle settle any disputes through mediation/ binding arbitration rather than through the legal system. It has to be someone that both parties feel comfortable with. This involves Josh coming to the realization that he may have to eat humble pie and make a few changes to Kiwifarms if he wants it to survive. I don't place a lot of confidence in this. The downside to this is that if Joshua agrees to this contractually and then refuses to honor his commitment, it could be seen as evidence that Josh acted in bad faith and make his position in court more vulnerable.
It would most likely go sideways the first time, and then the whole idea would wither on the vine like so many before it, though.