Actually twisting the cable increases the resistance which increases voltage loss and causes heat to build up. With the 12S prone to overheating the earth pin I would avoid twisting that too. Mine always passes over the A frame and I never had a problem.
A risk of being a pedant, but for purposes of clarity, a couple of twists in the outer cable won't increase resistance, what about the cables that come already curled? You are mistaking it with twisting the actual core of the cable.
Discounted Insurance Quotes for UKCampsite.co.uk visitors! Up to 12.5% off!
It seems odd that such a simple & effective technique can generate so much discussion, perhaps its worth explaining...
Before plugging in, take hold of cable just behind plug with both thumbs & fingers & put a couple of twists in without actually twisting plug itself. The amount of twists required is determined by the length of the cable & use minimum required to allow cable to stay well clear of ground.
Admittedly, my idea works primarily if you happen to have the AKS3004 hitch, but I pop my cables thru the hitch clamp handle as shown below and this works faultlessly.
No twisting of cables and allows perfect, unhindered movement of them throughout the tow, kept well clear of any damage from dragging.
Unrelated, but I always squirt a tad of contact cleaner into the plug and car sockets at each hitch too, and as yet, not had an ounce of trouble.
Many thanks for all the replies and ideas, I have used insulation tape and thankfully it seemed to work okay, however I will get the lead replaced and take more care when hitching up!