We had our tyres down to around 34psi (from memory) because we were towing.
Jamie normally runs them at around 24-28psi when we're offroad, lower on sand, and will drop them further to get out of a situation.
Not sure what pressures the Triton was running.
Our crew often run different tyre pressures. As Symon says, it's a personal choice.
Fingers crossed nobody needs one, let alone two, spares.
If in doubt, I've got a slightly used official lucky shamrock from Ireland going cheap