From my own experience, they explode at 80psi :-P
But I usually inflate mine (32mm) between 40 and 50psi ; I've done 6000 km with it and never had any trouble yet.
Not all rims can hold the same pressure. I inflated S-Ones to 100 psi on Stans grail and they hold just fine. Wouldn't hit the road with that, but sometimes I go up to 70 for fast tarmac riding, still no problems even with some dents in the rim
Also - brown wall gravel kings are now in stock.
If I run them tubeless at 70ish psi on proper tubeless ready rims will they explode and kill me?