elite controller or paddle re-map add on to existing controller

Not sure what you mean. There is a new "app" to let you re-map buttons (so red = blue etc) But if you want the extra physical rear buttons or paddles then these only come with the new control.

You could mod your controller - see "Ben Heck" on you tube - but that will of course invalidate your warranty etc.

Yes you can remap buttons now with any controller, that ability came with a recent update.

However the Elite Controller isn't just the ability to remap buttons and the little paddles, you can also adjust sensitivity to throttles, deadzones on the sticks etc

At the end of the day I personally don't see the point in spending roughly £120 on one controller, way too expensive (in my opinion).

Hello Antongallmetzer, this is Manuela. I'm an Independent Advisor and community user like you, ready to assist with this.

Not a Microsoft employee.

At the moment, the paddles in the Xbox elite controller can be mapped only to existing buttons on your controller (A, X, B, Y, etc.)

I have mapped buttons to the paddles with no issues at all, with the new elite controller you can now map TV functions such as volume up and down to the controller

The paddles on the Elite controller can only be mapped through the Xbox Accessories app on the Xbox One or Windows 10, otherwise they default to ABXY. They are mapped through the controller itself, you press a paddle on the controller, the controller then
sends the mapped command to the PC/Console. Thus they can only be mapped to duplicate other buttons on the controller and cannot be mapped to commands that are "outside" of the regular Xbox Controller inputs.

Basically they aren't an extra 4 buttons, rather an alternative 4 buttons.

Also, if they are not responding at all, try double tapping the sync button on the top of the controller. When turning the paddles off, you get 4 short bursts of vibration, when turning the paddles on, you get one longer burst of vibration.