ProMbrooke:in circuits 32 amps and below 99% of the VD during a fault is on the circuit itself and not the supply between the transformer and consumer unit.

Huh? Let's take some typical order-of-magnitude values for a suburban house. Ze might be around 0.2 Ohm, while R1+R2 for a radial socket might be about 0.4 Ohm. A short at/near the socket will result in about 2/3 of the VD in the circuit itself.  For it to be 99%, R1+R2 would have to be around 20 Ohm.

ProMbrooke:in circuits 32 amps and below 99% of the VD during a fault is on the circuit itself and not the supply between the transformer and consumer unit.

Huh? Let's take some typical order-of-magnitude values for a suburban house. Ze might be around 0.2 Ohm, while R1+R2 for a radial socket might be about 0.4 Ohm. A short at/near the socket will result in about 2/3 of the VD in the circuit itself.  For it to be 99%, R1+R2 would have to be around 20 Ohm.