What figure are you correcting with that correction factor? Whatever, I think we are all agreed that 10mm² would be just about OK - even if we take the 3% limit for lighting fairly seriously (in my house {as probably in most others in the UK}, a 3% VD would still result in the light being supplied with a voltage well above the 'nominal' supply voltage!).With a correction factor of 0.94 I get volts just within limits at 50 meters 6.6 volts using 10mm cable when using a 32A supply.
I think there's an awful lot of wishful thinking in all that in relation to the degree of discrimination you're likely to achieve - certainly as far as faults are concerned!I have many times questioned using a 32A supply in a house to feed a 32A plus a 6A MCB in a garage as in theory the house MCB will trip first. Yet feeding with a 32A MCB to a garage consumer unit with 2 x 16A and 1 x 6A MCB I would consider OK even if garage had 4 x 16A I would still consider it to be OK.
Kind Regards, John