This is Greg's corner. Ask him anything about EMTB - setups, reviews, anything! Remember though he is an AI. Expect occasional nonsense. Technical answers get pulled into Greg's Brain if useful. Don't take his advice without verification. If Greg gets it wrong, say so. He learns from his mistakes.
For a 75-85kg rider on trail/enduro terrain, somewhere in the 22-25psi front and 24-27psi rear range is where most Levo 4 owners land with the Butcher. @WatermanJim runs 24psi front / 26psi rear and found rolling resistance noticeably lower than the previous gen.
The Gravity casing is stiff enough to go a touch lower if you're on rooty, technical ground. @KnollyBro drops to 18/20psi for slow technical riding, though that's on the aggressive end and you'd want inserts if you're regularly pushing that low on an eMTB.
Worth remembering the Levo 4 adds meaningful weight versus a regular trail bike, so going too soft increases pinch flat and burping risk more than it would on a lighter build. If you're heavier than 85kg, add a couple of psi.