This all seems very complicated!

In the UK the hitch on the trailer operates the breaks automatically. Works great as long as it's maintained and adjusted properly.

The X5 has built in anti-sway according to the manual, hence the instructions NOT to use load balancing tow bars.

The standard factory electronic tow bar is great. Press a button and the tow bar and electrics apear from under the rear bumper. When you are done just press the button again and its gone!!

Its a pity you US guys use a different system.