Raspberry Pi high voltage supply soft-off circuit
U1 needs a pull-up or pull-down resistor on the input for when GPIO8 is low. I'd make R4 and R5 lower in value in case the switch needs a minimum wetting current to keep its contacts fresh and deoxidized (although if the regulators are connected this should be ok). I don't know what R3 is doing.

I'd put a capacitor to gnd on the switched 24 V side to ensure that power stays up even if the button press is a little short in duration. I'm struggling to see what D1 achieves.

Bottom line for me is simulate it first before committing to a PCB.