Is this still going on! ;P I’ve not got anything to do with it (never have, and probably never will enter one), but as it’s t’internet, I’ll throw an opinion in the hat!
I think the bottom line is, if you want to enter Steve’s events, you have to go by his rules unfortunately.
How they can make you take out PI insurance is a bit grey, but having it is not a bad idea, and would hope most riders would decide to do that on their own (but if not, that’s ok too, your body and all that), especially if they are racing the full series.
I don’t really understand how they can enforce you getting PI cover from any other insurer that the one recommended though…are they going to phone up the insurer of every competitor and ask “does this cover PI for riding our event?” Or do you have to get a cert specifically showing that your covered for gravity MTB races?