The carparthian is a very expensive defender edition, so I would say they are for the newer shape defender, hence why nobody on this poverty struck forum knows what they are!
Absolutely no idea!
Just thinking out loud that the car switches on X function and expects to see Y power draw, then when it sees excessive power draw I can see a potential issue.
You may find the new reverse lights draw to much power from the rev light circuit and the bcm might shut them down, if that is the case you will need some relays, fitting lower power bulbs in place of the rev light bulbs currently fitted might reduce the draw on the circuit.
If its for tow bar use take a look behind nearside cluster in the boot, think the plug is already in there.
If not 5 minutes with a test light will tell you all you need to know.