What is it you'll be towing?
You may find that the cables hang low with the extra length of the adaptor, so before towing make sure that you can secure them such that they are able to move freely when turning, but do not drag on the ground - might be worth having a bungy chord or some cable ties handy the first time you tow with the adaptors.
Another thought, will you be using a Alko style stability device which uses friction pads to clamp on to the tow bar? These are common on modern caravans. If so, then you'll need to sand back the painted finish on the tow ball with glass paper, and clean off with some brake fluid and kitchen roll, because if you don't it'll clog up the friction pads.